TMC 188/40 Motion Control Module
Common Problems and Solutions
Delta Computer Systems, Inc. 360/254-8688
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Common Problems and Solutions
Ladder program cannot access parameters or operate module
A) Usually this means the WY registers are not initialized or the slot is not configured properly
(P/C front panel indicator is flashing red-green). Before the TMC 188/40 will begin normal
operation, the eight WY registers must be initialized. The WY registers define the P/C's V
Memory locations where the TMC 188/40 reads and writes information. The initialization can
be done either with the CHART utility of TISOFT or with a ladder logic routine (see Appendix
E starting on page 103). To set up the WY registers using TISOFT:
1) Run
TISOFT
.
2) Put it in the
ON-LINE
mode.
3) Select
CHART
.
4) Select
BLDCHT
.
5) Enter
WY201 - WY208
(or whatever WY registers you are going to use).
6) Select
CHGVAL
to set the values for the eight WY registers. The values
entered are the addresses of the V Memory locations where the TMC 188/40
talks to (201, 251, etc. in the demo program).
7) When you have entered all eight values (including the checksum), verify the
P/C LED on the TMC 188/40 panel is green.
More information about the WY registers starts on page 9.
NOTE:
Once the TMC 188/40 finds a correct set of WY registers (including a valid checksum), it will not
read them again. Changes in the WY registers will not take effect until the TMC 188/40 is reset or
the power is cycled.
B) Verify the P/C is accessing the correct V Memory locations for the TMC 188/40 parameters.
During a move, the ACTUAL POSITION is erratic
Electrical noise or a defective transducer can cause this problem. Monitor STATUS word bit 6 to
determine if the module is detecting a transducer error. To reduce electrical noise do the
following:
A) Make sure the transducer wiring is separated from all other wiring (AC power, drive
cables, PWM servo valves, etc.)
B) Add a termination resistor as close to the transducer as possible (220 ohm for
Temposonics®).
C) Terminate the shield at module end, the transducer end, or both.
D) Install a pair of Delta Computer Systems' AMP/10 RS-422 converter cards. If a
Temposonics® II transducer is used, use the RPM option and one Delta AMP/10 card.
See TMC Wiring Diagrams starting on page 107.
TRANSDUCER COUNTS field not indicating transducer location
See "Axis indicator is constant red" below.
TRANSDUCER COUNTS field changes but output drive does not work
See "... axis comes to a halt for no apparent reason" below.
