ICS ELECTRONICS 4809A, Instruction Manual

Page: 79 / 131

3-28
3
Figure 3-1 shows the Status Reporting Structure. All Modbus Error codes
are placed in the Modbus Error Register at the top of the figure. If the proper
Event Status and Status Byte register bits are enabled, any Modbus Error
code will generate a SRQ. The commands to enable the bits are:
*ESE 64 ‘enables ESR bit 6
*SRE 32 ‘enables Status Byte bit 5
Some Modbus Errors set specific bits in the Questionable Event Register.
To generate a SRQ from a specific event, its bit must be enabled. The fol-
lowing commands enable SRQs for Timeouts and CRC errors only:
STAT:QUES:PTR #h3000 ‘enables positive going bits 12
and 13 to set bits in the
Questionable Event Register
STAT:QUES:ENAB #h3000 ‘enables Event bits 12 and 13
*SRE 8 ‘enables Status Byte bit 3
In both cases, the user needs to reset the event cause and clear the SRQ so
another error will cause another SRQ. In case one, this is done by reading
the Modbus Error Register with the E? query. In case two, the Questionable
Event Register must be read to clear the set event bits.
3.8.14 Personalizing the Unit’s IDN Message
The IDN message is changed with the CALIBRATE subsystem commands.
Change the IDN message when you want to personalize the unit, to iden-
tify the overall assembly as being from your company or to record product
history or revision dates. The IDN message is a lockable parameter and
if locked, needs to be unlocked before being changed. The format for the
IEEE 488.2 IDN message is four fields (company, model#, serial number
and revision) separated by commas and a maximum of 72 characters long.
The word “model” may not be used in an IEEE-488.2 IDN message. An
example IDN message change sequence is:
CAL:LOCK OFF ‘unlocks all parameters
CAL:IDN Acme Test Co, 101, s/n 007, Rev 1 07/08/30
'enter a new IDN message
*SAV 0 ‘saves lock status