Example Of Communicating Over The Gpib Bus - Extech Instruments 7470 Operation Manual

Standard Event Register
Bit Binar Event Register
y
weigh
t
0 1 Operation Complete
1 2 not used
2 4 Query Error
3 8 Device Error
4 16 Execution Error
5 32 Command Error
6 64 not used
7 128 Power On
*ESR?
9.8.8. 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, ESB bit 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.

9.9. 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 8000 volts do the following. First
select a memory by sending, for example the string for memory one ''FL 1", then send
the string "EV 8.0". This tells the instrument to set the voltage at 8.0kV. A string is a
list of ASCII characters, octal or hex bytes or special symbols.
include the quotation marks (" ") when sending the command string.
Enable Summary Register
Registe
r
ALL PASS
FAIL
ABORT
TEST IN PROCESS
Message Available (MAV)
Event Summary Bit (ESB)
Request Service (RQS) or
Master Summary Status
(MSS)
not used
*ESE *STB? | SPOLL
*ESE?
Status Byte Register
However do not
Enable
Registe
r
not
used
*SRE
*SRE?
67