IAI America ROBO Cylinder Series - Manual (Page 162)

5. Modbus RTU
154
Modbus
(5) Detailed explanation of registers
„ Target position specification register (PCMD)
This register specifies the target position in PTP positioning operation using absolute
coordinates. The value of this register is set in units of 0.01 mm in a range of –999999 to
999999 (FFF0BDC1 (Note) to 000F423F
H
). When the absolute coordinate is indicated, operation
starts with 0.2mm in front (Note 2) of the soft limit setting value as the target position if the setting
of the parameter exceeds the soft limit. The actuator will start moving when the lower word of
this register (symbol: PCMD, address: 9900
H
) is rewritten. In other words, a numerical
movement command can be issued simply by writing a target position in this register.
Note 1 To set a negative value, use a two’s complement.
Note 2 For a revolution axis set to Index Mode, the soft limit setting value is the target position.
„ Positioning band register (INP)
This register is used in two different ways depending on the type of operation.
The first way is the normal positioning operation, where it specifies the allowable difference
between the target position and current position to be used in the detection of position complete.
The second way is the push-motion operation, where it specifies the push-motion band. The
value of this register is set in units of 0.01 mm in a range of 1 to 999999 (1 to 000F423F
H
).
Whether the normal operation or push-motion operation is specified by the applicable bit in the
control flag specification register as explained later.
Changing this register alone will not start actuator movement.
„ Speed specification register (VCMD)
This register specifies the moving speed. The value of this register is set in units of 0.01
mm/sec in a range of 1 to 999999 (1 to 000F423F
H
). If the specified value exceeds the
maximum speed set by a parameter, an alarm will generate the moment a movement start
command is issued.
The actuator will start moving when this lower word of this register is rewritten. In other
words, the speed can be changed while the actuator is moving, simply by rewriting this register.