Wireless Network Confirmation: A Modbus Polling Tool Tutorial
Discover how to verify the functionality of your wireless network with a Modbus polling tool. This article provides a step-by-step guide for network confirmation.
Is your wireless network operating effectively? This tutorial demonstrates the use of a Modbus polling tool to confirm the health and reliability of your network. Ensure your heat trace system operates smoothly with this practical guide.
Resources
PSI Configuration Download Page
Scroll down to "Downloads" and then to "Software"
USB to RS-485 Converter that we use
Typical Modbus Configurations
Note that the below are standard Modbus communication parameter setups. Some heat trace controllers have the ability to modify this but these are normally what they are.
|
Manufacture |
Controller Type |
Protocol Option |
Serial Setup (Baud Rate, Data Bits, Parity, Stop Bits) |
| nVent (Digitrace, Raychem) | 920 | Modbus RTU (serial) Modbus TCP (Ethernet) |
9600,8,N,2 |
| nVent (Digitrace, Raychem) | 910 | Modbus RTU (serial) Modbus TCP (Ethernet) |
9600,8,N,2 |
| nVent (Digitrace, Raychem) | NGC30 | Modbus RTU (serial) Modbus TCP (Ethernet) |
9600,8,N,2 |
| nVent (Digitrace, Raychem) | NGC40 | Modbus RTU (serial) Modbus TCP (Ethernet) |
9600,8,N,2 |
| nVent (Digitrace, Raychem) | T2000 | Modbus RTU (serial) Modbus TCP (Ethernet) |
9600,8,N,2 |
| nVent (Digitrace, Raychem) | Elexant 4010i | Modbus RTU (serial) Modbus TCP (Ethernet) |
9600,8,N,1 |
| Thermon | TC202/201/102/101 | Modbus ASCII | 9600,7,N,2 |
| Thermon | TCM2 | Modbus RTU | 9600,8,N,1 |
| Thermon | TC1818a | Modbus ASCII Modbus RTD |
9600,7,N,2 9600,8,N,1 |
| Thermon | TCM18 | Modbus ASCII Modbus RTD |
9600,7,N,2 9600,8,N,1 |
Modbus Polling Registers for Testing
|
Manufacture |
Controller Type |
Modbus Address | Function Code | Register | Value |
| nVent (Digitrace, Raychem) | 920 | Set on controller | 3 | 1 | |
| nVent (Digitrace, Raychem) | 910 | Set on controller | 3 | 1 | |
| nVent (Digitrace, Raychem) | NGC30 | Set on controller | 3 | 1 | |
| nVent (Digitrace, Raychem) | NGC40 | Set on controller | 3 | 1 | |
| nVent (Digitrace, Raychem) | T2000 | Set on controller | 3 | 1 | |
| nVent (Digitrace, Raychem) | Elexant 4010i | Set on controller | 3 | 1 | |
| Thermon | TC202/201/102/101 | Set on controller | 3 | 103 | Maintaint Temp CCT1 |
| Thermon | TCM2 | Set on controller | 3 | 2 | Maintaint Temp CCT1 |
| Thermon | TC1818a | Set on controller | 3 | 103 | Maintaint Temp CCT1 |
| Thermon | TCM18 | Set on controller | 3 | 366 | Maintaint Temp CCT1 |
nVent 920 Controllers utilize a Modbus address and a Sub Address.
Sub address 0 (zero), you will use the register number mentioned above. For every subaddress 512 is to be added to the register. Sub Address 0 = Register+0, Sub Address 1 = Register+512, Address 2 = Register+(512*2),
Depending on what Modbus Polling tool you use an offset of 1 may be required for the register number. Ex. If you aren't haveing luck increase the register number by 1.
Whenever polling an ACSII controller ensure the quantity of data bits your polling is always 1 bit.