GE MM3, Instruction Manual, Page: 156 / 230

8–12 MM3 MOTOR MANAGER 3 – INSTRUCTION MANUAL
APPLICATIONS CHAPTER 8: COMMUNICATIONS
8.3 Applications
8.3.1 Performing
Commands
using Function
Code 10h
Commands can be performed using function code 16 as well as function code 5. When
using function code 16, the command function register must be written with a value of 5.
The command operation register must be written with a valid command operation
number. The command data registers must be written with valid data; this is dependent
upon the command operation.
The commands supported by the MM3 Motor Manager 3 are listed under format code F22
in the
Modbus Data Formats on page 8–43.
For example, consider a request for slave 17 to perform command operation 1 (reset): The
master/slave packets have the following format:
8.3.2 Storing
Addresses
using the
Broadcast
Command
The default setting for the communications address from the factory and after a setpoint
dump is off. The communication speed and parity default settings are 9600 baud with no
parity. We have provided a facility to store the communications address to any MM3 Motor
Manager 3 without using the keypad and display (typically chassis mount MM3 Motor
Manager 3s).
Make sure the master is transmitting to the MM3 Motor Manager 3 at 9600 baud and no
parity. After installing the MM3 Motor Manager 3 and ensuring communications is hooked
up, cycle control voltage to the MM3 Motor Manager 3 you wish to set the address for. This
will allow you to send a broadcast command with the new comms. address for the MM3
Motor Manager 3. The address must be set within 2 minutes of cycling power. Once the
new address is stored or the 2 minutes have elapsed, the MM3 Motor Manager 3 will ignore
all further attempts at changing the comms. address unless power is cycled again. The
address is changed using a broadcast command to comms. address 0 and a command
function code.
This procedure can be accomplished using the EnerVista MM3 Setup software; see chapter
4 for details.
Master Transmission Bytes Example Description
Slave address 1 11 message for slave 17
Function code 1 10 store multiple setpoints
Data starting address 2 11 60 setpoint address 1160h
Number of setpoints 2 00 02 2 setpoints = 4 bytes total
Byte count 1 04 4 bytes of data
Data word 1 2 00 05 data for address 1160h
Data word 2 2 00 01 data for address 1161h
CRC 2 76 87 computed CRC error code
Slave Response Bytes Example Description
Slave address 1 11 message from slave 17
Function code 1 10 store multiple setpoints
Data starting address 2 11 60 setpoint address 1160h
Number of setpoints 2 00 02 two setpoints
CRC 2 46 7A computed CRC error code
NOTE