JVL MAC050 User Manual page 465

7.1 Synchronous Movement
7.1.2 Optional settings Master
These settings ignore the Max Velocity register 5. If you want to vary the speed of the
master, you have to change the speed with the PLC control via register 65 Velocity V1.
The speed V2 is set to 0 rpm.
7.1.3 Optional Slave settings
These settings ensure wire-break-proof error transmission from the slave to the master.
The following setup of the slave is used that you have the same cyclic write register as
the master for the velocity (register 65 instead of register 5)
JVL A/S - User Manual - Integrated Servo Motors MAC050 - 4500 461