APPLICATION EXAMPLE
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 P485 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.
User map address | Parameter | User map data |
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| address |
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0000 | 0x0240 | 0x0100 |
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0001 | 0x0241 | 0x0101 |
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0002 | 0x0242 | 0x0102 |
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0003 | 0x0244 | 0x0103 |
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0004 | 0x0245 | 0x0104 |
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0005 | 0x0286 | 0x0105 |
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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
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.
P485 MODBUS TO PROFIBUS CONVERTER – USER GUIDE |
