Appendix - 81
Appendices
[3] Precautions during control
(1) Absolute position system (ABS)/Incremental system (INC)
When using FR-A700 series, absolute position system (ABS) cannot be
used. Even though "1: Enable (absolute position detection system)" is set in
the servo parameter "Absolute position detection system (PA03)", the servo
amplifier operates as incremental system.
• When the Simple Motion module is powered ON, OPR request is turned
ON and the current feed value is set to 0. (The current feed value is set to
0 even if only the power of inverter is turned OFF to ON.)
• Errors at absolute position system (1201 to 1205) are not detected.
(2) Control mode
Control modes that can be used are shown below.
• Position control mode (speed control including position control and position
loop)
• Speed control mode (speed control not including position loop)
• Torque control mode (torque control)
However, it is not available to switch to continuous operation to torque
control mode of expansion control "Speed-torque control". If the mode is
switched to continuous operation to torque control mode, the error
"Continuous operation to torque control not supported" (error code: 550)
occurs and the operation stops.
"1: Feedback torque" cannot be set in "Torque initial value selection (b4 to
b7)" of "[Pr.90] Operation setting for speed-torque control mode". If it is set,
the warning "Torque initial value selection invalid" (warning code: 521)
occurs and the command value immediately after switching is the same as
the case of selecting "0: Command torque".
(3) Driver communication
The driver communication is not supported. If the driver communication is
set in a servo parameter, the error "Driver communication setting error"
(error code: 975) will occur when the power is turned ON.
(4) Control mode switching of speed-torque control
The axis connected with FR-A700 series takes more time to switch the
control mode than the axis connected with the servo amplifier.
Switching operation
Switching time at
the servo amplifier use
Switching time at
FR-A700 series use
Position control mode Speed control mode
6 to 11ms 19 to 24ms
Speed control mode Position control mode
Position control mode Torque control mode
Torque control mode Position control mode
Speed control mode Torque control mode
Torque control mode Speed control mode