Siemens simatic et 200s Operating Instructions Manual page 256

1PosSSI/Analog
6.6 Functions of the 1PosSSI/Analog
Principle
What You Do
Provide the control interface with data corresponding to the
JOB.
Check the JOB_ACK feedback bit is at 0
Switch the JOB_REQ control bit from 1 to 0
Switch the JOB_REQ control bit from 1 to 0
Only when JOB_ACK=0 can you activate a new JOB again.
Figure 6-6
256
Control and Feedback Signals with JOBs
Response of the 1PosSSI/Analog
The 1PosSSI/Analog sets the feedback bit JOB_ACK = 1
You can tell from this that activation has been detected by
the 1PosSSI/Analog and when JOB_ERR = 0, the JOB is
executed.
When a reference signal is evaluated, the
•
1PosSSI/Analog sets the SYNC = 0 feedback bit at the
same time.
In the case of the latch function, the 1PosSSI/Analog
•
sets the feedback bit LATCH_DONE = 0 at the same
time.
All the other JOBs are thus executed.
•
The JOB is not executed when JOB_ERR = 1.
The 1PosSSI/Analog sets the feedback bit JOB_ACK = 0
When a reference signal is evaluated, the 1PosSSI/Analog
sets the feedback bit SYNC = 1 when the function has been
executed.
In the case of the latch function, the 1PosSSI/Analog sets
the feedback bit LATCH_DONE = 1 when the function has
been executed.
Operating Instructions, 05/2007, A5E00124871-04
ET 200S Positioning