Allen-Bradley GuardPLC 1753, Справочник по безопасности

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50 Publication 1753-RM002C-EN-P - September 2008
Chapter 4 GuardPLC Controller and GuardPLC I/O Output Channels
Analog Outputs in the
1755-OF8 Module
The information in this section applies to the analog outputs of the
1753-OF8 module.
General
The analog outputs on the 1755-OF8 GuardPLC 2000 (AB-AO) module
are written once per cycle and stored internally. This functionality is
tested by the module itself.
The analog output module can be configured for current or voltage
output via DIP switches on the module.
The analog output circuits contain current/voltage monitoring, read
back and testing of parallel output circuits, and two additional safety
switches for the safe disconnection of the output circuit in the event of
failure. Thus, the safe condition is achieved at an output current of
0 mA and an output voltage of 0V DC.
In addition, the respective channel status signals can be evaluated in
the application program.
Test Routines
The module is automatically tested in operation. These are the
essential test functions.
•
Safety 1oo2 A/D Microprocessor system.
•
Double read back of output signals.
•
Test for cross-talk between the outputs.
•
Check of the integrated safety switch-off.
ATTENTION
Check the switch settings before inserting the module into the
chassis, and make sure that the settings in the application
program coincide with the hardware configuration.
Configuring the hardware for current output and the application
program for voltage output results in erroneous behavior of the
module.
ATTENTION
-
Unused analog voltage outputs must be left open. Unused
analog current outputs must be short-circuited.