12 - 24
MELSEC-Q
12 CONTROL SUB FUNCTIONS
[2] Control details
The following drawing shows the operation of th e torque limit function.
50%
0%
100%
0%
100% 50%
Torque limited at the parameter
torque limit setting value (100%)
Various operations
PLC READY signal [Y0]
Pr.17 Torque limit setting value
Cd.22 New torque value
Md.35 Torque limit stored value
Torque limited at the parameter
torque limit setting value (50%)
Fig. 12.13 Torque limit function operation
[3] Precautions during control
(1) When limiting the torque at the " Pr.17 Torque limit setting value", confirm
that " Cd.22 New torque value " is set to "0". If this parameter is set to a
value besides "0", the " Cd.22 New torque value" will be validated, and the
torque will be limited at that value. (Refer to Section 12.5.4 "Torque c hange
function" for details about the "new torque value".)
(2) When the “ Pr.54 OPR torque limit value “exceeds the “ Pr.17 Torque
limit setting value”, an error occurs. (Error code: 995)
(3) When limiting the torque, a D/A converter m odule and drive unit in which
torque limit commands by analog voltage are poss ible.
(4) When the operation is stopped by torque limiting, the droop pulse will remain
in the deviation counter. If a "deviation cou nter clear" is carried out by
issuing an external signal at this time, positional deviati on will occur when
the operation is continued. If the load torq ue is eliminated, operation for the
amount of droop pulses will be carried out.