This tutorial describes the guidelines and procedures for communicating the main quantities measured by the PH1600 with a Nexto Xpress series PLC using the Modbus RTU protocol.
Components
Software: MasterTool IEC XE v3.34
PLC: XP300
Multimeter: PH1600
Tutorial Sections
1. ARCHITECTURE
2. ELECTRICAL CONNECTION
2.1. Three-phase and 4-wire connection
2.2. Three-phase and 3-wire connection
3. PH1600 CONFIGURATIONS
3.1. Connection type
3.2. Connection type
4. MODBUS COMMUNICATION
4.1. PH1600 Modbus Table
4.2. Adding Device
4.3. Declare Variables in a GVL
4.4. Mappings and Requests
4.4.1. Mappings
4.4.2. Requests
1. ARCHITECTURE
In the architecture of this tutorial, to perform Modbus RTU communication, an AL2306 cable was used, connecting terminals 58 (A) and 59 (B) of the PH1600 to terminals D+ and D- of the XP300, respectively.
NOTE: All devices must be connected to a power supply compatible with their input voltage.
2. ELECTRICAL CONNECTION
In this topic, the possible connections on the PH1600 will be described.
2.1. Three-phase and 4-wire connection
2.2. Three-phase and 3-wire connection
Attention: Note that it is necessary to have knowledge of the system phases for the correct connection of the voltage and current measurement cables, otherwise the phase sequence will be inverted, causing the PH1600 to measure incorrectly.
3. PH1600 CONFIGURATIONS
In this topic, the necessary configurations for the PH1600 will be described.
3.1. Connection type
To select the connection type, access the 'ner' option and change the number as necessary. For a 3-phase and 3-wire connection, enter a value other than 0000. For a 3-phase and 4-wire connection, enter the value 0000, as shown in the image below:
3.2. Communication Adjustment
In 'Con1', you can configure the port address, speed, parity, stop bits, and data bits. To adjust each parameter, follow the steps indicated in the image below:
These parameters must be configured according to the serial port parameters of the PLC in MasterTool. In the example, we used the following values:
So, on the PH1600 we must configure the following:
Sn = 0001
Baud = 0004
Dara = 0001
4. MODBUS COMMUNICATION
In this topic, it will be demonstrated how to map the main quantities to allow reading on the XP300.
4.1. PH1600 Modbus Table
4.2. Adding Device
Right-click on ‘COM1’ and select ‘Add Device’. Then a new window will be displayed. Click on the ‘+’ symbol next to the word ‘MODBUS’ and then do the same on ‘MODBUS Master’. Finally, double-click on ‘MODBUS Symbol RTU Master’.
Repeat the same procedure with the device created earlier and add the 'MODBUS Device'.
4.3. Declare Variables in a GVL
Declare the variables in a GVL, as shown in the image below:
4.4. Mappings and Requests
Since the declared variables are of type INT, the data type will be 'Holding Register'. As this is a read operation, configure as 'Read'. In the 'Data Start Address' field, enter the address as described in the PH1600 Modbus Table mentioned in topic 4.1.
4.4.1. Mappings
4.4.2. Requests
The Modbus RTU communication configuration is complete. Log in to the XP300 and set it to RUN mode. Then, access the GVL you created and check the values being received.
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