Siemens SIMATIC ET 200S - Page 292

1PosSSI/Analog
6.6 Functions of the 1PosSSI/Analog
ET 200S Positioning
292 Operating Instructions, 05/2007, A5E00124871-04
Wire Break/Short Circuit of the Encoder Signals Response of the 1PosSSI/Analog
Prerequisite:
• To detect errors of the encoder signals, you must
enable the "Encoder signal diagnostics" parameter.
Causes:
• Wire break or short circuit of the encoder signals at
terminals 1, 5 or 4, 8.
• The parameters for the SSI encoder do not
correspond to the encoder connected.
What to Do:
• Check the wiring and correct the short circuit.
• Compare the parameter assignment with the
technical specifications of the encoder.
• Acknowledge the error with the EXTF_ACK control
bit.
• The current MODEs relative positioning and absolute
positioning are stopped; it is not possible to start a new run
in these MODEs.
– Analog output QV+ is set to 0 V
– Digital output:
if the direction is assigned parameters for the DO
function, the digital output OUT=0 is set
– Feedback bit POS_ERR = 1
– Feedback bit POS_DONE = 0
• Feedback bit ERR_ENCODER = 1
• Feedback bit SYNC = 0
• Generate channel-specific diagnostics
• Waits for error acknowledgment EXTF_ACK
• Inching MODE is not affected by this error.
Errors in the Control of MODEs and JOBs
POS_ERR Response of the 1PosSSI/Analog
Causes:
• Certain requirements or conditions have not been
met at the start of a MODE
• The MODE started is not executed.
• The current run is stopped.
– Analog output is slowed down to 0 V using the ramp.
– Feedback bit POS_ERR = 1
– Feedback bit POS_DONE = 0
JOB_ERR Response of the 1PosSSI/Analog
Causes:
• Certain requirements or conditions have not been
met at the activation of a JOB
• The activated JOB is not executed.
– Feedback bit JOB_ERR = 1
Generating a Channel-Specific Diagnostics
In the event of parameter assignment errors (short circuit of the sensor supply or open
circuit/short circuit of the sensor signals), the 1PosSSI/Analog generates a channel-specific
diagnostics for the connected CPU/master. To do this, you must enable the Group
Diagnostics parameter (see the
Distributed I/O Device manual).