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

RG-MHMOD 26
Drive Control & Communication
7 Quick Start Instructions
Follow these Quick Start instructions to use ModBus Communications for basic network control of an MCH
drive. These instructions are a reprint of Application Note AN0034,
Basic Network Control of the MCH Drive
using Modbus™ Communications. To download the MCH product manual or application note visit the AC
Tech Technical Library at http://www.lenze-actech.com.
7.1 Initial Settings
1. Set the Modbus Master to 9600 bps with 8 data bits, no parity and 2 stop bits. The MCH series drive
does NOT support any other baud rates or data formats.
2. Set Parameter 58 (Serial Address) to the desired network address that the Modbus master will poll.
Valid Modbus addresses are 1-247.
TIP - Avoid using address 1. Most Modbus devices ship with a default address of 1. As duplicate
addressing on a Modbus network is not allowed, this can lead to conflicts when replacing and
commissioning nodes. To avoid this it is recommended that you do not set the slave address to 1.
3. The MCH series drive has the provision for a watchdog timer to monitor network communications to the
drive. The timer is fixed at a value of 10 seconds. If the drive is under network control (with Parameter
30 (Control) set to SERIAL AUTO or S AUTO/NO HND) and the master does not communicate with the
MCH drive for longer than the 10 second timeout period, the drive will trip to FLWR/SERIAL fault. The
timer can either be enabled or disabled as outlined in the next step.
4. Set Parameter 57 (Serial Communication) to either W/TIMER or W/O TIMR as desired in order for serial
communication to function.
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 TB1 needs to be asserted in order for the drive to start. If you will not
be starting/stopping the drive via the terminal strip, simply jumper the TB1 input to TB2 for a basic MCH
drive or jumper B3 to B4 for an MCH drive with bypass.
a. To Start and control the MCH drive from the network AND be able to start the drive locally in HAND
mode, set Parameter 30 (Control) to SERIAL AUTO
b. To start and control the MCH drive exclusively from the network, set Parameter 30 (Control) to S
AUTO/NO HND.
2. Use either Modbus function code 16 with a length of 1 or Modbus function code 06 to perform any
writes to the drive.