Associated Research HYPOTULTRA III 7620, Operation And Service Manual, Page: 98 / 148

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8.9.8. GPIB Service Request
The service request capability is not available with the RS-232 interface. The SRQ line will be
activated only after one or more of the service request functions have been enabled using the
Status Byte Enable Register command *SRE.
The status byte bit assignments are as described in the previous section for status reporting.
When the instrument has requested service, the enabled bit or bits and the RQS bit 6 will be
active or 1. Bit 4, 5, and 7 are not used and will be set to false, or 0 for all status byte reads.
After the serial poll (SPOLL) is executed the RQS bit will be cleared to 0, and the remaining
bits will remain unchanged. The status byte will not change value until the event register is read
and cleared for the corresponding status byte bit.
For example after the All Pass SRQ has been enabled, when the test(s) have finished with pass
indications the instrument will set the hardware SRQ line and output the status byte of 41 hex.
This means that bit 6 and bit 0 are set to a value of 1. After reading the status byte the status
byte value will change to 01 hex.
8.10. Example of Communicating Over the GPIB Bus
To write commands over the IEEE bus you must enter the code that is specific to the software
language you are using. Then follow the example below:
To set the output voltage across the IEEE bus at 1240 volts do the following. First select the
ACW step for example by sending the string for step one
''SS 1" then send the string "EV
1240" : This tells the instrument to set the AC voltage at 1240 volts. A string is a list of ASCII
characters, octal or hex bytes or special symbols, enclosed in double quotes.
If the step has already been selected to ACW mode and you wish to set the Ramp Up time of
the ACW test across the IEEE bus at 10 seconds, do the following, send the string
"ERU
10.00". This tells the instrument to set the AC Ramp Up time at 10.00 seconds.
To set outputs 1 & 2 of the internal scanner to High, outputs 3 & 4 to Low and outputs 4-8 to
Off type in the following string,
"EIS HHLLOOOO" , after the ACW Test Function has been
selected. All channels not being specifically set will automatically be set to “O” open.
To read the live testing data, first send the string "TD?" then send the GPIB command to read.
For RS-232 the response will be sent automatically to the controller. The instrument will send a
string of parameters separated by commas for each meter on the display example the data for an
ACW test might be as follows:
"01,ACW,Dwell,3.00,1.25,0.00,2.5" this represents an ACW
test at step 1, 3.00KV output voltage, 1.25mA total current, 0.00mA real current and the
elapsed time for Dwell cycle is 2.5 seconds.