Confidence Mode; Using Relay Verification - Racal Instruments 1256 Manual

1256 User Manual

Confidence Mode

Using Relay
Verification
Advanced SCPI Operations 8-18
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and driver failures. The 1256 switching system offers two methods
for identifying and locating these problems.
The 1256 supports an operational mode that performs a high-level
system-wide verification. When Confidence Mode is enabled, the
1256 checks the status of all switches after it closes or opens any
of them. The syntax for the command is shown below:
[:ROUTe]
:MONitor
[:STATE] { ON | 1 | OFF | 0 }
If any relay is not in the correct state and Confidence Mode is
enabled, the 1256 pushes an error message onto the system error
queue and asserts the "Execution Error" bit in the Event Status
Register.
If the 1256 is accessed through the GPIB interface, this condition
can further be made to generate an SRQ interrupt. This is
accomplished by writing a "1" into the "Execution Error" mask bit of
the Standard Event Status Register and a "1" into the "ESB" mask
bit of the Service Request Enable Register.
When Confidence Mode is enabled, commands are executed more
slowly because of the time consumed in reading the status of all
relays. The amount of slowdown depends on the quantity and
types of switch modules that are installed.
The 1256 system also supports the ability to verify that a switch or
a range of switches is closed or open.
commands is shown below:
[:ROUTe]
:VERify
:ALL?
:MASK <channel list>, 0 | 1 | X
:MASK? <channel list>
The 1260 line of switching cards used in the 1256 typically utilizes
open-drain or open-collector drivers. A separate signal between
the coil of each relay and associated driver feeds back into the
1256 for verification and confidence mode checks.
Verification is somewhat different than confidence mode which is
enabled with the MONITOR:STATE command. With confidence
mode enabled, the 1256 verifies the state of all relays in a system
Publication No. 980855 Rev. A
The syntax for these
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