Lenze SCF Series Drives Modbus Communications - Manual (Page 30)

RG-SFMOD 26
Drive Control & Communication
7.2 Drive Control
1. Start/Stop Control: Please be advised that while the drive is under network control the local STOP
circuit is always enabled. Input 1 needs to be asserted in order for the drive to start. If you will be
starting/stopping the drive solely via network control, simply jumper the TB1 input to TB2.
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.
To only control the drive over the network you can write a value of 0 to the drive’s Modbus register
40049 (AC Tech register 48).
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 SCF drive is 225.
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 Manual Mode: 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 200H to
Modbus register 40002 (the drive’s control register). This step is not necessary if there are no other
speed references setup on any TB-13x terminal.
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 the stop method programmed in P04, 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. P17 must be set to 2 in
order for this command to be accepted.
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 the speed of the drive, set P05 (Standard Speed Source) to 01
(Keypad) and write the speed to the Keypad 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.