RS-485 Network Interface Module Type 1 (NIM-1)

With the introduction of our new product line (Chameleon+), 2023 (or while supplies last) marks the end of production for legacy Chameleon (EOL Announcement). We will continue to provide technical support on all EOL products. In addition, we will continue to repair the EOL products for as long as replacement parts can be acquired.

Features and Benefits

  • 2-Wire Isolated RS-485 Interface with Selectable On-board Biasing and Termination
  • Protocols: Master or Slave Modbus RTU/ASCII, Master or Slave FairNET, and Custom ASCII or Binary Messaging
  • Network Configuration Tools Integrated in Design Pad G3
  • Multiple NIMs Can Be Combined to Form Gateway, Bridge, Routing, and/or Redundant Connection Functionality
  • Selectable Baud Rates from 75 bps to 1 Mbps
  • -40°C to +65°C (-40°F to +149°F) Operating Range
  • MIL-STD-901D Grade A for High Impact Shock
  • MIL-STD-167B for Vibration
  • MIL-STD-461E for Electro-Magnetic Interference (EMI)
  • Supports Hot Swapping

The Chameleon RS-485 Network Interface Module (NIM-1) offers high-speed communications using FairNET, Modbus ASCII (master and slave), Modbus RTU (master and slave), Custom ASCII, or Custom Binary protocols. FairNET provides both deterministic and non-deterministic messaging, automatic bus mediation, and a robust master-slave architecture.

You can network up to 256 NIM-1 modules and achieve data rates as high as 1 Mbps. NIM-1 units have built-in biasing and termination circuitry for easy and reliable network configuration.

As with all Chameleon modules, NIM-1 units are hot-swappable: to replace one, you can simply swap the front panel (with attached processing board) and the unit is back online—there is no need to shut off the power and there is no need to detach connectors. They also provide unequaled ruggedness. They are specifically designed for sustained operation in severe environments, including those characterized by extreme shock, vibration, electro-magnetic interference, temperature, and/or humidity. The fully-sealed enclosure (sealing end-caps not pictured) ensures long-lasting operation in the grimiest settings.

Operating Ambient Temperature Range -40°C to 65°C
Storage/Transport Ambient Temperature Range -40°C to 85°C
High Impact Shock MIL-STD-901D, Grade A
Mechanical Vibration MIL-STD-167B, 0-50Hz
Electro-Magnetic Interference MIL-STD-461E
Facial/Housing Protection NEMA 1,2,4,4X,5,6,12,12K,13
Maximum Power Consumption 2.8W
Network Capacity One module can drive 32 standard RS-485 unit loads or 256 NIM-1 modules
Network Capacity 256 NIM-1 modules can be driven by a standard RS-485 transceiver
Max Baud Rate 1 Mbit / Second
Electrostatic Discharge Protection +/- 15 KV Human Body model
Signal Electrical Isolation from Control Circuitry 1500 VDC
Cable Fault Protection No spurious signals on receiver inputs if network cable is open or shorted
Biasing On-board 470Ω high and low
Termination On-board 110Ω
Supported Cable Diameters Two glands 0.24”-0.47”; two glands 0.16”-0.31”
Supported Wire Gauges 16-28 AWG
Status Readout One three-color (red/yellow/green) LED Indicator
IR Wireless Interface 115kbps SIR
Weight 1.3 lbs
Front Panel Dimensions 2.5” W x 6” L
Enclosure Height 3″H

The following part numbers can be used when ordering the Network Interface Module Type 1 (NIM-1).

Fairmount Part Number


01012-002 NIM-1 with Gray Enclosure
01012-302 NIM-1 with Black Enclosure (without Stuffing Tubes)
11030-200 NIM-1 Active Board and Gray Cover
11030-250 NIM-1 Active Board and Black Cover
01014-002 NIM-1 Half-Size Gray Enclosure with Wiring Hub Assembly
01014-302 NIM-1 Half-Size Black Enclosure and Wiring Hub Assembly (without Stuffing Tubes)
11018-100 NIM-1 Wiring Hub Assembly