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User Manual
Appendix B
GFK-1742F
Jan 2020
DSM314 Communications Request Instructions
413
First Rung: The MOVE WORD instruction moves hexadecimal number 1840 into %AQ00001,
the first word of the Immediate Command. The low byte value (40) of this number specifies
the Select Return Data Immediate Command. The high byte value (18) specifies the Mode
selection for Parameter Data.
The MOVE INT instruction moves a decimal value of 1, indicating Parameter 1, into
%AQ00002. This commands that the value in DSM Parameter 1 be written to the User
Selected Data double word for Axis 1, %AI00021/AI00022 in this example.
Note:
The actual %AI addresses used for any DSM module are specified when the module is configured.
The TMR THOUS (thousandths) timer instruction produces a 45-millisecond time delay after
the Select Return Data Immediate Command is sent. This is required because User Selected
Data is not available in the ladder until at least 3 sweeps or 20 milliseconds (whichever is
greater) elapses after the Select Return Data Immediate Command is sent. Since the sweep
time in this example is 14 milliseconds, this 45-millisecond delay ensures that the Parameter
1 data will be present in the User Selected Data double word before the Equal instruction in
the next rung executes. Note that contact %M00200 must stay ON long enough for the TMR
timer to time out and enable the second rung.
Second Rung: After the 45-millisecond delay in the previous rung elapses, contact %M00202
closes and enables this rung. In this rung, a double integer EQUAL instruction compares the
value in %R00208/R00209 (the source of the value sent by the COMM REQ to DSM
Parameter 1) with the value returned from Parameter 1 in %AI00021/AI00022. If the values
are equal, coil “Verify” wil
l turn on.