RG-TDMOD 28
Drive Control & Communication
7.2 Drive Control
1. Please be advised that while the drive is under network control the local STOP circuit is always enabled.
Input 28 needs to be asserted in order for the drive to start. If you will not be using start/stop simply
jumper TB28 input to TB20.
2. Use either Modbus function code 16 with a length of 1 or Modbus function code 06 to perform any
writes to the drive.
3. Unlocking the Drive.
The first write necessary to the drive to perform any function (start,change speed, change a parameter,
etc) needs to be an unlock.
If you want to both control the drive and alter any programming parameters then write the drive’s
programming password to Modbus register 40049. The default password for the TMD drive is 0.
You should only need to send the unlock command once after power up. As long as the communications
do not timeout you should not need to write another unlock to the drive before writing any other
function.
4. Setting the Drive to Network Speed reference:
In order for the drive to respond to speed commands written to the keypad speed register the drive
must be put into manual mode. To do this write a value of 100H to Modbus register 40002 (the drive’s
control register).
7.3 Basic Drive Commands
The following are the basic drive commands. ONLY ONE OF THESE CAN BE DONE AT A TIME:
1. To STOP the drive using COAST TO STOP, write a value of 0004hex to Modbus register 40002 (AC Tech
register 1).
2. To Start the drive write a value of 0008hex to Modbus register 40002.
3. To Set Reverse direction write a value of 0040hex to Modbus register 40002.
4. To Set Forward direction (the drive powers up with forward direction already selected) write a value of
0080hex to Modbus register 40002.
5. If you want the network to control speed of the drive, write the speed to the Serial Speed Command
Register, Modbus register 40041 (AC Tech register 40). Speed is written in 0.1Hz (so 412 would be
41.2 Hz). In this mode the drive’s initial speed reference on power up will be the last speed written to
the drive.
