Modbus to Analog Hub For Controlling Analog Devices with RS485 Interface

Banner Engineering is well-known and trusted in the automation world for selling various components, with product offerings spanning sensors and measuring devices to lighting and vision systems. Recently, Banner added to their line of Modbus converters with the R90C Modbus to Analog Hub.

 

Modbus Converters

Developed by Modicon (now owned by Schneider Electric) in the late 70s, Modbus is a serial communication sometimes referred to as RS485. Modbus communication can commute to multiple devices on the same serial network by using addressed messages.

 

The R90C Converter Series, a serial analog output hub. Image used courtesy of Banner Engineering

 

Banner Engineering has an entire product line that converts industrial communication protocols or signals into Modbus messages, including IO-Link, analog signals, and discrete signals. These converters do not reside in an electrical cabinet taking up real estate. Some of these converters are installed inline or can be installed directly in the field or on the machine. The versatility of these converters reduces wiring and maintenance, which reduces cost and downtime. 

 

R90C Modbus to Analog Hub

Banner Engineering’s R90C 4-port Modbus to analog converters will convert serial messages sent from a Modbus RTU or PLC into analog outputs.

Typically with analog outputs, you need to decide if you need current or voltage output, but with the R90C, you simply change the value of a specific register. Each port has its own register where you set your desired analog output. Another register is provided to change the output type: 0 = off, 1 = voltage, and 2 = current. The configurable outputs are 0-10 VDC or 4-20 ma on each port. The R90C uses industry-standard 12 mm threaded connectors for easy connection in the field.

For easy identification, the R90C is equipped with matching LED indicators on both sides for each output that shows the status of the analog signal, along with an LED for displaying the Modbus signal. The converter operates on 24 VDC and is protected from reverse polarity and transient voltages. The R90C comes with three IP ratings: IP65, IP67, and IP68, and it is capable of temperatures from -40°C to 70°C.

 

Banner’s R90C analog converter allows integrators and control engineers to easily add analog output to a system that uses Modbus or RS485. Image used courtesy of Crystal Kwok

 

Modbus to Analog Applications

Analog control is still a very important part of automation. Some inexpensive or small devices don’t support fieldbus protocols such as Ethernet/IP or ProfiNet but do support analog signals for control. Adding analog outputs can be costly, especially when dealing with older equipment that is no longer supported. Your only choice may be to replace the entire PLC, which would cost even more.

Banner’s solution with the R90C analog converter allows integrators and control engineers to easily add analog output to a system that uses Modbus or RS485 without purchasing expensive output cards or replacing outdated equipment.