TMC 188/40 Motion Control Module
V Memory
Delta Computer Systems, Inc. 360/254-8688
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V Memory Example
You can see a complete "picture" of V Memory on the next page. Specific V Memory addresses are
used in this example, but the addresses you use in a given application will depend on your P/C ladder
program.
VINIT
refers to initialization parameters that you write to V Memory using the P/C.
VWRITE
refers to
dynamic control parameters that you write to V Memory using the P/C.
VREAD
refers to status
information written to V Memory by the TMC 188/40 and monitored by the P/C. One exception to
these conventions is the COMMAND
parameter in VWRITE. This location is bidirectional between
the TMC 188/40 and P/C. It is written to and monitored by both the P/C and TMC 188/40. Please
refer to pages 38 through 42 for more information on the COMMAND parameters.
During every scan of the P/C the VREAD and VWRITE parameters are transferred to and from the
TMC 188/40. The VINIT parameters are moved from V Memory to the TMC 188/40
only
when a 'P'
command is issued using the COMMAND location of the VWRITE parameters. To inform the P/C the
'P' command was completed, the TMC 188/40 sets the COMMAND VWRITE V Memory location to 0.
The P/C ladder program must monitor the COMMAND location after each command is issued to
ensure it was completed.
