GE D485, Instruction Manual

Page: 75 / 96

APPLICATION EXAMPLE
D485 MODBUS TO DEVICENET CONVERTER – USER GUIDE 9–3
Modbus user map setup
DESCRIPTION
GE Multilin Relays and Meters support the Modbus User Map feature in their software. This
feature can be used with the D485 to reduce the number of Modbus transactions and
improve communication speed.
PQMII USER MAP
There are six parameters to be read from PQMII as indicated in the previous section.
Normally, six read input register command transactions are required to read these
parameters. However, these parameters can be grouped together with the Modbus User
Map feature and read using only one read input register command transaction.
Set the Modbus User Map for the PQMII as follows.
1.
Start the Enervista PQMII Setup software.
2. Establish communication between the device and PC.
3. Select the Setpoint > User Map menu item.
4. Set the user map registers as follows and save to the meter.
Figure 9-1: PQMII meter user map setting
The six parameters are now mapped to user memory map data at 0x0100 to 0x0106.
These parameters can now be read by one
Read input data register command at 0x0100
with register length = 7 words (note that average phase voltage value is in 32-bit).
MM2 USER MAP As indicated earlier, there are five parameters to be read from MM2. Normally, five read
input register command transactions are required to read these five parameters. However,
all the parameters can be grouped together using the Modbus User Map feature and read
using only one read input register command transaction.
Set the Modbus User Map for the MM2 as follows.
1.
Start the MM2PC software.
2. Establish communications between the device and PC.
3. Select the Setpoint > User Map menu item.
User map address Parameter User map data
address
0000 0x0240 0x0100
0001 0x0241 0x0101
0002 0x0242 0x0102
0003 0x0244 0x0103
0004 0x0245 0x0104
0005 0x0286 0x0105