Using The User-Definable Memory Map - GE Multilin MM3 Motor Manager 3 Instruction Manual

CHAPTER 8: COMMUNICATIONS
8.3.3 Using the
User-definable
Memory Map
MM3 MOTOR MANAGER 3 – INSTRUCTION MANUAL
For example, to store communications address 25 to a new MM3 Motor Manager 3 without
a display, we have the following master/slave packet format. The master/slave packets
have the following format:
Master transmission
Slave address
Function code
Data starting address
Number of setpoints
Byte count
Data word 1
Data word 2
Data word 3
CRC
Slave response
Slave address
Function code
Data starting address
Number of setpoints
CRC
The MM3 Motor Manager 3 contains a user-definable area in the memory map. This area
allows re-mapping of the addresses of any actual values or setpoints registers. The user-
definable area has two sections:
1. A register index area (addresses 1280h to 12f7h) that contains 120 actual
values or setpoints register addresses.
2. A register area (addresses 0100h to 0177h) that contains the data at the
addresses in the register index.
Register data that is separated in the rest of the memory map may be re-mapped to
adjacent register addresses in the user-definable registers area. This is accomplished by
writing to register addresses in the user-definable register index area. This allows for
improved throughput of data and can eliminate the need for multiple read command
sequences. The user-definable register index is stored as a setpoint and therefore it is
"remembered" even when the power is removed.
For example, if the values of
STATUS (register address 0023h) are required to be read from a MM3 Motor Manager 3,
their addresses may be re-mapped as follows:
Write 0031h to address 1280h (user-definable register index 0000)
using Modbus function code 06 or 16.
Write 0023h to address 1281h (user-definable register index 0001)
using Modbus function code 06 or 16.
The EnerVista MM3 Setup software can be used to write these locations to the user-
definable register index. For example,
Select Communication > Troubleshooting menu item.
Bytes Example
1 11
1 10
2 11 60
2 00 03
1 06
2 00 05
2 00 10
2 00 19
2 0B 8C
Bytes Example
1 11
1 10
2 11 60
2 00 03
2 84 FB
PHASE A CURRENT (register address 0031h) and
APPLICATIONS
Description
message for slave 17
store multiple setpoints
setpoint address 1160h
3 setpoints = 6 bytes total
6 bytes of data
data for address 1160h
data for address 1161h
data for address 1162h
computed CRC error code
Description
message from slave 17
store multiple setpoints
setpoint address 1160h
three setpoints
computed CRC error code
DRIVE
8–13