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Frequently Asked Questions from other E-Prime users
The following topics are commonly asked about by E-Prime users.
General
- Is E-Prime accurate to the millisecond?
- What do I do with the green or purple hardware key?
- I keep receiving the following error message: This system is in violation of the licensing agreement...attach hardware key to your computer that was shipped with your order of E-Prime
- How do I jump to the end of a trial based on an incorrect response?
- How do I use the Label object to jump outside of a procedure?
- Why is there no opportunity for a response when I run a trial?
- How Do I Display the Current Trial Number?
- How do I pause a currently running experiment?
- Why is E-DataAid ignoring all numbers with commas when analyzing the data?
- Why do I get a compile error "Script too Large to Compile" when I attempt to run my experiment?
- How do I represent Missing Data for export to SPSS?
Port Communication
- How do I send a signal to communicate with an external device?
- How do I receive a signal from an external device?
- How can I notify external equipment at the exact time that an event occurs in E-Prime?
- General Serial Device Information
- General Parallel Port Information
Is E-Prime accurate to the millisecond?
This is a complex question. We've literally conducted millions of timing tests on the E-Prime system. The simple answer is that E-Prime is accurate for psychological research, BUT you should review our detailed chapter on Critical Timing in the E-Prime User's Guide Chapter 3 to get the full answer. Documentation can be found on the E-Prime installation CD.
What do I do with the green or purple hardware key?
Each E-Prime system is shipped with a green parallel hardware key or a purple USB hardware key. This key must be connected to the parallel or USB port on the machine you intend to install E-Prime. Please note the following distinctions between the license types:
Single License: The hardware key must be in place on the parallel or serial port during installation AND while using E-Studio. It is not required when collecting data with E-Run. You may move it from machine to machine (e.g. work at the office/lab during the day and take it home to work after dinner). The important thing is that you must have it in place when installing and while using E-Studio.
Multi-Pack License: These systems are conceptually identical to a single license. The term 'multi-pack' is applied because the systems were purchased on the same purchase order.
Site Licenses: The hardware key is only required to be in place on the parallel or USB port during installations.
I am receiving the following error message when I attempt to open E-Studio, "This system is in violation of the licensing agreement...attach hardware key to your computer that was shipped with your order of E-Prime".
This may be the result of a port conflict within your machine. Please work through the following checklist to determine how to resolve the problem...
1. Is there a virus checker running on the problem machine? If so, shut it off. Virus scanning programs are the leading cause of problems like this, as they interfere with "normal" machine functioning.
2. Is there anything else attached to the key (i.e. a printer)? If so, disconnect it and try again. While the hardware key is a pass-through and should allow an external connection, there is always a chance that that external device could be interfering with port communication.
3. Can you confirm that the machine's parallel port is in "standard" or "output" or "SPP" mode? This is done in the system BIOS. Since this can be complicated and is machine specific, we suggest that you have your in-house technical support check the BIOS settings for you. If the port is in Bi-Directional, ECP, or EPP, you should switch it to Standard. Otherwise the key will not be able to be recognized properly.
4. Toshiba computers have a icon in the Control Panel called "Toshiba HWSetup". If you go to the Parallel/Printer tab you can chose the setting "Standard Bi-directional". This setting allows the program to communicate with the key.
5. Try updating the copy protection file manually simply click on the following link and follow the instructions: http://www.pstnet.com/downloads/misc/HaspUserSetup.exe
If none of the above suggestions resolve the error message then please answer the following questions and send to our web based support at http://www.pstnet.com/e-prime/support.
Please include your beta serial number.
Does this happen on any other machine?
Is the problem machine a laptop?
Has there ever been another version of E-Prime on this machine before?
Please include your machine specs (i.e., Make/Model of Machine, Operating System)
Was computer purchased new? When was it purchased?
Are the hardware key problems consistent or occasional?
Does your machine have an USB port?
How do I program E-Prime to jump to the end of the trial based on an incorrect response?
The Label object allows you to mark a location in a procedure and to jump to this location based on some criterion (e.g., incorrect response). The sample experiment named NestingXRT (C:\My Experiments\Samples) is included with each install to illustrate this functionality. However, in the sample experiment the criterion to jump is based on any type of input.
The NestingXRT sample experiment can be modified as described below to illustrate just how to jump to the end of a trial if an incorrect response is detected or to continue with the trial when a response is correct.
First, in the TrialList you must create another attribute named IncorrectAnswer. This attribute will be used to indicate when the subject presses an incorrect answer to jump to the end of the trial. Essentially, the values would be the opposite values of the correct answer attribute. For example:
|
|
CorrectAnswer |
IncorrectAnswer |
|---|---|---|
|
Trial1 |
1 |
2 |
|
Trial2 |
2 |
1 |
|
Trial3 |
2 |
1 |
|
Trial4 |
2 |
1 |
In order to jump based on an incorrect response you must specify two keyboard input devices within the Duration/Input tab of the object collecting the response (i.e., Stimulus). The second keyboard device is being added because a different action will be taken based on the accuracy of the response. This feature makes it possible to set up two keyboard devices which are looking for different responses.
To add another keyboard input device locate the Duration/Input tab on the Properties pages for the object collecting the input and simply click Add and select Keyboard. Each keyboard input device will be associated with either a correct response or an incorrect response by referencing the attributes created in the TrialList (i.e., CorrectAnswer and IncorrectAnswer). Again, the two devices are necessary since different actions will be taken based on the accuracy of the response.
If an incorrect answer is detected then it will jump to a specific location within your experiment. To specify the location you wish to jump to you need to insert a Label Object into your experiment. To create a Label Object you simply click and drag the object from the toolbar and place it in the Structure View at the location you wish to jump (i.e., end of the trial). In this experiment a Label Object has already been created called DoFeedback. Please notice that the Name and Label properties in the properties window must be entered accordingly on the Label Object.
To link the Label Object to the key press which allows the jump, locate the Duration/Input tab for the object collecting the input (i.e., Stimulus). Next locate the keyboard device which will be detecting the IncorrectAnswer. The following properties must be set as specified below for the keyboard input device which will detect an incorrect response:
|
Allowable Input |
[IncorrectAnswer] |
|---|---|
|
Correct Input |
[CorrectAnswer] |
|
Input Action |
Jump |
|
Jump Label |
DoFeedback |
The Jump Label refers to the Label Object (i.e., DoFeedback). Hence when an incorrect response is detected it will jump to the end of your trial and proceed to the next trial. As for the second keyboard input device which will detect a correct response, you must set the properties on the Duration/Input tab as follows:
|
Allowable Input |
[CorrectAnswer] |
|---|---|
|
Correct Input |
[CorrectAnswer] |
|
Input Action |
Terminate |
This will allow the steps within the trial to continue.
Is there any way to use the Label object to jump outside of a procedure?
E-Prime does not allow you to jump outside a procedure. A procedure is a timeline of events, hence when you jump to the end of the procedure you are skipping over the events that occur in one single trial. To jump outside a procedure you must terminate the List Object based on some criterion. To do this you must include an InLine Object containing a small amount of script. The InLine Object would be placed following the object that is accepting the input. The following lines of script would be implemented in order to terminate the List Object if an incorrect answer was received. The lines of script below assume that the input is collected via a TextDisplay named “Stimulus”, and the List Object that is to be terminated is named "TrialList".
If Stimulus.ACC = 0 then TrialList.Terminate
In order to allow extended input you must include a blank TextDisplay object and a Label Object in your procedure. A TextDisplay object would be used instead of a WAIT object so that the stimulus display is cleared (overwritten). The blank TextDisplay object allows more time for input and the Label Object instructs where to go in the trial once input has been collected. Without the blank TextDisplay object following the Image Display the image will terminate after 250 msec giving you no time to respond. The Duration is a Run-Time Method of the Image Display object, so it will only display the image for that amount of time. The Input Options on the Duration/Input tab are essentially on a different thread, which still allows input once the present object is terminated. Hence, you would include a blank TextDisplay object to enable more time to collect input. A Label Object must also be included because if input is collected within the 250 msec allowed then the Label Object would jump over the blank TextDisplay object to enable the feedback.
How Do I Display the Current Trial Number?
There are several methods that may be used to display the trial number on each trial. First, the Sample property of the List object (i.e., TheListName.Sample) returns the sequential number of the currently selected sample from the currently running List object. The Sample property may be used within brackets in an object (e.g., TextDisplay or other display object) to reference the currently running sample/trial number. For example, if you wish to display the trial number while sampling from a List object named “TrialList”, you can use the following syntax placed on an object in the Procedure that is being called from TrialList…
Trial #[TrialList.Sample]
The square brackets indicate to E-Prime that the value inside is an attribute reference to resolve (in this case the reference will resolve to the current Sample property of the TrialList). The “Trial #” portion of the example above simply appears as text in the display, and may be deleted or changed however you wish.
To make the reference more generic, use the “Running” attribute to query what the name of the currently running List object is, and then determine what the sample number is. That is, insert the following syntax on the object used to display the trial number…
Trial #[[Running].Sample]
The Running attribute reference will resolve the value of “Running” to the name of the currently running List object, and the Sample property would then be returned for that List object.
A second method of displaying the trial number is to use an InLine object to insert script to set an attribute that may then be referenced in an object. In script, the syntax for determining the current sample of the currently running List object and setting it to an attribute is as below. A second line of script is added to indicate how you might include an attribute to indicate the total number of trials…
c.SetAttrib “TrialNum”, c.GetAttrib(c.GetAttrib(“Running”) & “.Sample”)
c.SetAttrib “TotalTrials”, 10
This script sets the TrialNum attribute equal to the currently selected sample of the currently running List object. The TrialNum attribute may then be referenced in a TextDisplay or other object to display the trial number. To do so, insert the following syntax into the object used to display the trial number (e.g., TextDisplay):
Trial #[TrialNum] of [TotalTrials]
The script above would result in the display appearing as “Trial #1 out of 10”. Again, the text outside of the brackets may be deleted or changed as desired.
How do I pause an experiment at Run-Time?
Currently, you cannot pause the running of E-Run, you are only allowed to terminate the run. This feature is expected to be included in future releases following v1.x. To abort an experiment early simply press Ctrl + Alt + Shift to terminate the E-Run program. A dialog box will be displayed showing the "Experiment terminated by user" message, click OK. Next a dialog box will appear showing the "Abnormal Program Termination" message, click OK. This information can also be found on the back on the green sheet of the Getting Started guide.
Why is E-DataAid ignoring all numbers with commas when analyzing the data?
This is an internationalization issue in which all numbers with a decimal point are converted to commas (e.g., 0,05 rather then 0.05).
E-Prime v1.x is currently only available for the Western European/US version of Windows 95/98/ME/2000/XP. Problems that focus on internationalization issues (i.e., fonts, date formats, negative number formats) will be addressed with the Windows 2000 release. For now there are many workaround solutions available to convert the number format to decimal points rather than commas.
1. Go to the Start>Settings>Control Panel>Regional Settings and set the region/locale to be English (United States). In Win95/98 this setting is a global machine setting, hence this will effect other applications (i.e., Excel, Word, etc.). You may want to switch this back after collecting the data from the test program. Note that changing this setting typically forces you to restart Windows. This option is listed first because this is the ONLY environment under which the software is EXPLICITLY DESIGNED to work with correctly and formally tested under.
2. Go to the Start>Settings>Control Panel>Regional Settings and change the decimal separator to "." rather than ",". This is a bit less harsh than the first option because it allows you to customize just one of the settings for your current locale, but keep all other locale specific information in-tact. However, again in Win95/98 this setting is a global machine setting so it will effect other applications.
3. Change the code in the test program to use the Str() function instead of CStr() since Str() does NOT use locale information when converting the number. However Str() has the side effect of always putting either a leading space (if the number is positive) or a leading minus sign (if the number is negative) as the first character. Unfortunately leading space will also likely cause E-DataAid to interpret the data as string so you will also need to use the Trim() function around the Str() function to remove the leading white space [e.g. str1 = Trim( Str( dblNumber ) )]
4. Use the Find/Replace feature in E-DataAid to replace "," with "." within those columns that are effected.
5. Export the data and analyze it in Excel (which likely does use locale information to interpret the data).
Why do I get a compile error "Script too Large to Compile" when I attempt to run my experiment?
This occurs when you have a relatively large number of Lists and/or exemplars in your program. However, this can be resolved by changing the LoadMethod property within the List Object to "Embedded". Setting the LoadMethod to "Script" essentially writes a line of code for each attribute to each row of a List separately, thereby creating too many lines of code to compile. Setting the LoadMethod to "Embedded" will allow the List to be loaded from an embedded data section within the script. If the LoadMethod is currently set to "Embedded" and you continue to receive this error message, try re-evaluating the structure of your experiment to minimize the number of Lists and/or exemplars in your program.
Representation of Missing Data for export to SPSS
The Export command within E-DataAid offers an option to export to StatView and SPSS format. The default values for the representation of missing value are appropriate for Statview format, but SPSS requires missing data to be represented by a period rather than a null value. The workaround for exporting to SPSS is to use the Other option within the Export dialog to set the value for missing data to a period through the drop-down list. All other default settings within the Other option are appropriate for SPSS format and do not need to be changed.
Send a Signal to an External Device
Support for sending a signal to an external device (e.g., another machine, EEG) is available in E-Prime via port communications or through writing your own Windows DLLs.
For port communications, a small amount of script must be used in an InLine Object. To send a signal to the port, you should use the WritePort command in an Inline in your experiment. The parameters for WritePort are as follows:
WritePort address, value
The address of your port can be found by selecting "System" from the Windows Control Panel, clicking on the Device Manager tab, and navigating to Ports. Select the parallel (LPT or printer) port, click the Properties button, and select the Resources tab. The address of the currently accessible port will be shown.
In the WritePort command, the port address may be specified in decimal or hexadecimal notation. Please refer to the Val function in the E-Basic Help file for further explanation. When using hexadecimal notation, E-Basic requires "&H" to be inserted prior to the address:
WritePort &Haddress, value
The most common parallel port address is (in decimal) 888, which translates in hexadecimal notation to 378. However, we strongly recommend that you refer to your own System properties to find the available port address on your own machine.
You must also remember that, when writing to the parallel port, you are sending 8 bits of data at once. For the WritePort command, the value parameter is translated into binary notation to determine the bit pattern. Since this binary representation corresponds to a specific bit representation, you must send a value which translates (in binary) to send the appropriate bit representation. Essentially, you should write a "1" to any bit whose corresponding pin you wish to turn "on." A "0" is written to any bit whose corresponding pin you wish to turn "off". If you were to send all "0"'s to the port, the binary notation for this would be 000000000. To send a signal to bit number '2', the binary notation would translate to 00000010.
The bit pattern then corresponds to the pin connections. Bits are either 0-based or 1-based. Pins are always 1-based.
***** Please Note: The first available bit to pin connection begins at bit number 1 and at pin number 2. You cannot send a signal to pin number one.*****
Therefore, if you wanted to turn on bit number one an a 1-based bit pattern, and leave the rest off, you would send a signal of "1" to pin 2, and a signal of 0 to pins 3-9. In binary notation, this would be written as 00000001. In decimal or hexadecimal notation, this would translate to "1". If your port address were (in hexadecimal) 378, the Write Port syntax for this would be:
WritePort &H378, 1
Bit to pin mapping is relatively standard for the parallel port. Please refer to documentation for your hardware and/or port address for a mapping of bits to pins.
E-Prime is capable of sending a signal to the port for interfacing with an external device. The receipt and handling of the signal by the other machine is the responsibility of the user. With the WritePort command, E-Prime may be used to trigger an event (e.g., signal an external device to begin data acquisition) or notify an external device of an event (e.g., in order to mark the event in the data collected by the external device).
When sending more than a TTL pulse to the port, you must write your own Windows DLLs. The only information and/or support PST can offer is to direct you to the DECLARE statement in E-Basic Help. Essentially, you can bring the library of calls from into E-Prime by copying and pasting them into the User script of your experiment. In doing so, you will likely no longer use E-Prime's "WritePort" command for port communications, but will rather use the specific commands you have imported. Writing Windows DLLs is best done by a professional programmer, and is beyond the scope of PST's support for E-Prime.
Receive a Signal from an External Device
The Port Device is capable of communicating with any programmable port.
Essentially, the Port Device is activated via the Experiment Object and in the property pages of the object that collects input. Once the Port Device has been added in the Experiment Object, you must configure it to your port settings (port address, bits).
The address of your port can be found by selecting "System" from the Windows Control Panel, clicking on the Device Manager tab, and navigating to Ports. Select the parallel (LPT or printer) port, click the Properties button, and select the Resources tab. The address of the currently accessible port will be shown.
*Please note: In order to designate an input address you must add "1" to the output address, so that if your port address, in hexadecimal notation is 378, you would enter "379" in the Port Devices "address" field.
The mask value is set by default to -1, which has no effect on bits.
To use the Port Device in the Property Pages, you must do the following:
1. Click on the Duration/Input tab
2. Click "Add"
3. Select the Port Device
4. Set input properties for the Port Device
The Allowable Input for the Port Device is expressed as individual characters representing a bit position (1-8, for 8-bit port setting). The bit pattern, therefore, corresponds to the pin connections. Bits are either 0-based or 1-based. Pins are always 1-based. In most cases, if you are simply looking for any bit to change and trigger E-Prime, you may enter "any" in the Allowable Input field for the input object.
The CorrectInput is a single bit which identifies which bit position is expected to change on this input. When reading through the port, only 5 bits can be changed with input. Bits 1-3 are always indeterminate; bits 4-8 can be changed. Therefore, your input would generally be a number or numbers from 4-8, if the "any" setting was not appropriate.
Identification of bits is solely the user's responsibility. Please refer to documentation for your hardware and/or port address for a mapping of bits to pins.
Once you have added, configured, and enable the Port Device as an Input Device, E-Prime can read input through the Port without the need for any complicated E-Basic script.
Notify external equipment at the exact time that an event occurs in E-Prime.
There are three approaches you can take, depending on the degree of control you need over the signaling mechanism and which type of port device you need to use (parallel/digital I/O card vs serial communications).
Option 1 –Parallel Port Triggers:
In v1.0, onset and offset signal properties are available on E-Objects. These properties will allow triggers to be sent at the exact time of an object's onset/offset and will greatly improve your ability to keep timing consistent with stimuli. The properties include:
X.OnsetSignalEnabled
X.OnsetSignalPort
X.OnsetSignalData
X.OffsetSignalEnabled
X.OffsetSignalPort
X.OffsetSignalData
where "X" is the actual name of the object on which the property is being set.
You can find these properties fully documented under the general RteRunnableInputObject topic in the E-Basic Online Help. Note that you will need to specify the address of your port via the xxxSignalPort property, and the value you are sending via the xxxSignalData. If you do not know how to find these values, please click here General Port Information.
The onset and offset signal properties direct E-Prime to internally send a specific value to a specified I/O port at the exact time a stimulus onsets or offsets. The I/O port used is typically a parallel digital I/O port rather than a serial port; i.e., each bit within the port has some assigned meaning by the researcher.
For this type of signaling you can typically use the built-in parallel port, or alternatively, install a register addressable digital I/O card. If you use the default parallel port there is typically no hardware initialization needed. If you use a third party digital I/O card, you often have to configure the card once at the beginning of the experiment by using the WritePort E-Basic command to send a value to a configuration value to a designated configuration port. This step typically programs the registers/ports on the card as input or output. Refer to your cards programming manual for specific instructions on this step.
Assume objects named "Prime" and "Probe", and a parallel port address of &H378 in the following example. If you wanted each object to send a signal to the parallel port upon its onset, you would create an Inline object at the beginning of the experiment and type in the following script:
Prime.OnsetSignalEnabled = True
Prime.OnsetSignalPort = &H378
Prime.OnsetSignalData = &H01
Probe.OnsetSignalEnabled = True
Probe.OnsetSignalPort = &H378
Probe.OnsetSignalData = &H02
In this example, "Prime" sends a signal to bit 0, and "Probe" sends a signal to bit 1, each time the object is run in the script.
It is typically only necessary to set these properties once, at the beginning of the experiment. If the OnsetSignalData value changes under some conditions, however, you will need to change the value of the property in an InLine that runs prior to the the object that sends the signal.
By default, sending an OnsetSignal from an object keeps the bit high until it is shut off by the next object that runs. If you want to do a toggle, there are two options:
1. Use a WritePort command in an InLine, following this object. Write a "0" to all bits.
2. Use the corresponding OffsetSignalEnabled/Port/Data properties to reset the bits all back to 0s at the offset of the object.
If you need to control the duration of the pulse, you will also need to manipulate the Duration and PreRelease properties of the object that sends it, until the desired pulse width is achieved (i.e. by adjusting the time between the object’s onset and offset). Refer to the timing diagrams in “Appendix E: Timing of Object Execution” in the E-Prime User’s Guide for a description of the different timing intervals within the execution of an object in E-Prime.
Option 2 – Parallel or Serial Triggers before Stimulus:
You can alternatively intersperse script between each object in the trial sequence and use either the WritePort command or the SerialDevice and its associated methods to communicate with the external device. However, using this method will NOT guarantee that the signals are precisely synchronized with the stimulus. With this method, the signal should occur within one refresh, and this refresh will be specific to the refresh rate of your own monitor.
To enable a WritePort pulse that is synchronized within one refresh of the next event, you should insert an InLine directly preceding the event object on the procedure. You will then use the following script in the InLine (where your WritePort information is customized to your experiment):
Display.WaitForVerticalBlank
WritePort address, val
If you were sending the signal to the serial port, you would use the script:
Display.WaitForVerticalBlank
Serial.WriteString “strData”
This assumes that the SerialDevice is added to the experiment and the serial communication properties port id, baud rate, start bits, parity, stop bits, etc. are configured the same on both machines. The strData parameter becomes the actual string representing the data to be written to the serial device. If you need general information on how to use the Serial Device in E-Prime, please click here General Serial Device.
This approach attempts to send a signal a consistent 1 screen refresh before the stimulus. Again, the best you can hope to achieve using this secondary approach is some constant signal time before the stimulus. Note that this approach can also interact with the PreRelease mechanism in E-Prime and can even send the signal at the wrong time if you do not fully understand how PreRelease works in E-Prime and how to adjust for it. You can refer to the Critical Timing chapter, Chapter 3, of the E-Prime User's Guide for a thorough explanation of PreRelease in E-Prime.
Option 3 – Parallel or Serial Triggers after Stimulus:
The final approach is send the signal after the stimulus is presented. This approach requires that you set the PreRelease property for the object to the same value as its Duration, which forces the object to exit its Run method as soon as the stimulus is finished being presented. You would then send the signal by inserting an InLine after each object in the trial sequence:
For a parallel port device:
WritePort address, val
Or alternatively use the following for a Serial port
Serial.WriteString “strData”
The down side of this approach is that each object will require a variable duration to complete the stimulus presentation and perform internal housekeeping duties prior to its Run method being exited. Thus, there can be a small amount of variability between the time the stimulus is presented and the time the signal is sent. This delay is typically constant for similar stimuli, but can vary from machine to machine.
General Serial Device Information
For Knowledge Base information about the General Parallel Port see 1319- INFO: General Serial Device Information: http://www.pstnet.com/e-prime/support/kb.asp?TopicID=1319 on the E-Prime Web Support Site.
Serial communication is facilitated by addition of the Serial device in E-Prime.
You can add the Serial device to your experiment via the Devices tab of the Experiment Object's property pages. Addition of the Serial Device on the Experiment Object allows you to specify port settings for the Serial Device directly on the Experiment Object.
Once you have added the Serial Device, you will still need to use E-Basic script within an InLine for communication with the serial port. The Serial device's properties and methods have been fully documented in the Serial Device Object topic in the OnLine E-Basic Help. You can also find a sample experiment, demonstrating use of the Serial device, in the Samples area of v1.0 web support. Note that if you plan to use the Serial Device, you may need a null modem connected to your serial port to properly handle the data being passed through the port.
General Parallel Port Information
For Knowledge Base information about the General Parallel Port see 1320 - INFO: General Parallel Port Information: http://www.pstnet.com/e-prime/support/kb.asp?TopicID=1320 on the E-Prime Web Support Site.
The address of your port can be found by selecting "System" from the Windows Control Panel, clicking on the Device Manager tab, and navigating to Ports. Select the parallel (LPT or printer) port, click the Properties button, and select the Resources tab. The address of the currently accessible port will be shown.
The port address may be specified in decimal or hexadecimal notation. When using hexadecimal notation, E-Basic requires "&H" to be inserted prior to the address. For example, the most common parallel port address is (in decimal) 888, which translates in hexadecimal notation to 378. This would, therefore, be written as: &H378 in E-Prime.
Note: Make sure parallel port mode is set correctly in the BIOS, e.g. common terms are 'Output only' or 'Standard'
The value parameter can also be written in decimal or hexadecimal notation. The value is translated into binary notation which represents a specific bit pattern. The bit pattern then corresponds to the pin connections. Bits are either 0-based or 1-based. Pins are always 1-based.
You must remember that, when writing to the parallel port, you are sending 8 bits of data at once. You will write a "1" to any bit whose corresponding pin you wish to turn "on." A "0" is written to any bit whose corresponding pin you wish to turn "off".
Note: The first available bit to pin connection begins at bit number 1 and at pin number 2. You cannot send a signal to pin number one.
Therefore, if you wanted to turn on bit number one on a 1-based bit pattern, and leave the rest off, you would send a signal of "1" to pin 2, and a signal of 0 to pins 3-9. In binary notation, this would be written as 00000001. In decimal or hexadecimal notation, this would translate to "1". If your port address were (in hexadecimal) 378, the Write Port syntax for this would be:
WritePort &H378, 1
If using OnsetSignals, the proper syntax would be:
ObjectName.OnsetSignalEnabled = True
ObjectName.OnsetSignalPort = &H378
ObjectName.OnsetSignalData = 1
Assuming that you have connected the external equipment to the pin associated with bit 0, the external hardware would see +5V or a logical "1" on the pin. You could verify this with an o-scope or hand held multi-meter by connecting the signal lead to the pin representing bit 0 and the ground lead to a ground pin (typically pins 18-25).
Bit to pin mapping is relatively standard for the parallel port. Please refer to documentation for your hardware and/or port address for a mapping of bits to pins.
E-Prime is capable of sending a signal to the port for interfacing with an external device. The receipt and handling of the signal by the other machine is the responsibility of the user.
