Acromag: How to Use Wireless Remote I/O Cost-Effectively


Defining the Problem:

A wastewater treatment facility needs a cost-effective wireless remote I/O solution to bring measurements for water level, turbidity, PH, temperature, and phosphates back to their SCADA control room. The SCADA system can accept analog and discrete inputs as well as Modbus® RTU and Modbus TCP/IP. They have sensors for these measurements that output 4 to 20mA but local ordinances won’t allow overhead wiring. This would mean having to run wires underground, which is costly; especially since they need to cross a parking lot in this case.

System Requirements:

This remote I/O must be able to transmit five analog current signals wirelessly, as well as be cost-effective.

Implementing a Wireless I/O Solution:

  1. The Vertu® VWB2201 is a simple point-to-point wireless bridge that has one channel of analog current or voltage input, one channel of analog current output, and four discrete I/O, as well as Modbus RTU with RS-485 Modbus pass-through communication.
  2. The 913MB-0900 is a 4-channel current input module that is a Modbus RTU slave.
  3. The VWB2201 has a primary unit and a secondary unit. It’s important to note that the primary unit must be connected to the network that has the Modbus RTU Master controller.

Learn more about Acromag Wireless I/O here.

VWB2201: Vertu Point-to-Point Wireless Analog and Digital I/O Signal Bridge

913MB-0900: Modbus RTU analog DC current input module; four current input channels

Why Acromag for this I/O Solution:

Pairing the VWB2201 with the 913MB-0900 allows the customer to add the data points they need without the added expense of unnecessary equipment and installation costs. The added benefit of four channels of discrete I/O can also be used for control or alarms. Acromag has additional Modbus RTU units for analog or discrete inputs and outputs, as well as temperature and pulse/frequency input units, so more data points can be added as needed.

Acromag is a Michigan-based manufacturer that has been in business for over 60 years. All Acromag products are manufactured in the USA.


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