Industrial Networking Tech Note 10 - TNIN10

Abstract

This document provides a step by step procedure for configuring Modbus I/O transfer on the RAM to poll any Modbus Ethernet Slave device.

Products

RAM Cellular RTU

Use Case: Data Concentrator

The RAM Cellular RTU can be used as a Modbus Data Concentrator.  This document steps through the configuration one I/O Transfer (Modbus Write) enabling the RAM to move data to and from any Modbus Ethernet Slave device.  Many Transfers can be added to meet the application requirements (Read & Write transfers). Data that is gathered by the RAM can then be used in a variety of application scenarios including and not limited to:

1. Easy remote connectivity and monitoring
2. Transferred as DNP3 data
3. Controlled using the Event Engine
4. Used for Alarming and Notification (Email/SMS)

Required Software:

Web browser

Required Firmware

Any 4.xx firmware

Log into the RAM Web Browser

1. Referring to Figure 1, type the device’s LAN/WAN IP, port 10000 into a web browser

Figure 1.

2. User Name: admin

3. Password: Last six digits of the device’s serial number

Figure 2.

Configure RAM Modbus Station Parameters

1. Navigate to: Automation – Modbus – Local Station, then referring to Figure 3:

2. Set Enable Modbus to Yes.

3. Define Station Name, RAM in this case.

4. Define Station Number, 1 in this case.

5. Define Modbus Local Port (Standard TCP Port for Modbus is 502).

Figure 3.

6. Click Save.

Add a Remote Station Definition

1. Navigate to Automation – Modbus – Remote Station

2. Click Add, then referring to Figure 4:

3. Enter Station Name for the remote device, ModbusSlave in this case

4. Enter remote device Station Number (Modbus station address), 2 in this case.

5. Enter the Remote IP Address, 192.168.0.2 in this case.

6. Enter Remote IP Port (IP port 502 is the standard default Modbus)

7. Optionally enter the Station Online address.

Figure 4.

8. Click Finish. The Remote Station will appear in the table shown in Figure 5.

Figure 5.

9. Click Save.

Configure I/O Transfers

1. Navigate to I/O Transfers found at the bottom of the page or via Automation - Modbus - I/O Transfers

2. Click Add

3. Define the first I/O Transfer as needed, an example is shown in Figure 6.

Figure 6.

NOTE: the Scan Enable Address may be added to control when the IO Transfer is active or inactive. The Event Engine may be used to control this behavior.

4. Click Finish

5. Repeat steps 2 through 4 as needed.

Testing: Use Test I/O to monitor values on RAM

1. Navigate to Automation - I/O Setting - Test I/O, then referring to Figure 7:

2. Add Raw I/O for both Local DO (1 > 8)

3. Select Start

Figure 7.

NOTE: Scrolling down may be required to view all registers

Topology:

Figure 8.

Note: This is a very simple topology used to define the setup for this document, however many network variations can be supported.

Disclaimer

It is the customer's responsibility to review the advice provided herein and its applicability to the system. Red Lion makes no representation about specific knowledge of the customer's system or the specific performance of the system. Red Lion is not responsible for any damage to equipment or connected systems. The use of this document is at your own risk. Red Lion standard product warranty applies.

Red Lion Technical Support

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