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RMD680/RMD681

RMD680/RMD681

RMD680/RMD681

Product catalog summary
Overview: The RMD680 is an 8/16-channel universal input transmitter and multiplexer designed for applications requiring multiple input measurements. It features a serial output RS-485 and supports various input types including mA, V, mV, thermocouples, and RTD sensors.
Specifications:
  • Process Inputs: 0/4..20mA, -20..+20mA, 0..10V, -10..+10V
  • mV Input Range: -100..+100mV
  • Thermocouples Supported: B, C, D, E, G, J, K, L, N, R, S, T
  • RTD Sensors Supported: Pt100, Pt1000, Ni, Cu, KTY83
  • Resistance Input Range: 0..40000 ohm
  • Analog Output: 0/4..20 mA or 0..10V
  • Alarm Relays: 2, with common alarms
  • Display: Front panel display
  • Programming: Via front panel keys or RS-485 interface
  • Protocols: Modbus RTU and Nokeval SCL
  • Power Supply: 24 VDC, galvanically isolated
Functionality: The RMD680 is designed for efficient measurement and data transfer to PCs or PLCs. It supports up to 16 input channels, each programmable for different sensors, with a measurement rate of 12 channels per second. It can connect up to 32 devices on the same serial bus, allowing for rapid data acquisition.
Communication: Measurements can be accessed via RS-485 using Modbus RTU or Nokeval SCL protocols. The device supports multiplexing, enabling economical data acquisition in systems with limited analog inputs or serial communication capabilities.
Configuration and Compatibility: The device can be configured using Mekuwin software or directly via front panel keys. It is compatible with WinX, PromoLog, and third-party software supporting Modbus communication.
Technical Specifications:
  • RTD Sensors: Range -200..+700°C, Accuracy 0.05% + 0.25°C
  • Thermocouples: Various ranges with specific linearization errors
  • Process Inputs: mA and V inputs with specific accuracies and resistances
  • Serial Interface: RS-485, various baud rates, and protocols
  • Alarms: 2 relays, max 250VAC, 2A resistive
  • Analog Output: 0/4-20mA and 0-10V, accuracy 0.05%
  • General Information: Operating temperature -10..60°C, EMC compliance, DIN-rail installation
Options: Configuration software MekuWin, USB-RS485 converter DCS770.
See more

Catalog excerpts

RMD680/RMD681-1

www.nokeval.com FI-37100 Nokia, Finland Fax. +358-3-3422066 Process inputs: 0/4..20mA, -20..+20mA, 0..10V, -10..+10V mV input range: -100..+100mV Thermocouples: B,C,D,E,G,J,K,L,N,R,S,T J RTD sensors: Pt100, Pt1000, Ni, Cu, KTY83 Resistance input range: 0..40000 ohm 1 analog output 0/4..20 mA or 0..10V, channel selection with digital inputs or min/max value 2 alarm relays, with common alarms Display on front panel Programming with front panel keys or with serial interface RS-485 Modbus RTU and Nokeval SCL serial protocols Power supply 24 VDC, galvanically isolated from inputs Multichannel transmitter RMD680 has been designed for applications where lots of inputs have to be measured and transferred economically either to PC or PLC. Transmitter has 16 input channels, which can be programmed individually for different sensors. Measurement rate is 12 channels per second. Measurements can be read either by serial interface RS-485 using Modbus RTU or Nokeval SCL protocol or with one analog output. Up to 32 devices can be connected to the same serial bus without repeaters. It takes 30ms to read all channels from one device, thus 512 channels can be read in less than second. When analog output is used, output channel is selected with a 4-bit digital input. Transmitter has also 4-bit digital input for enabling its analog output thus total channel count can be increased to a maximum of 256 channels by connecting mA outputs of several devices in parallel. This way all channels from one device can be read in less than one second. Every channel can be configured totally individually. Channel inputs are differential thus channels don’t affect on each other. Transmitter has two alarm relays, that can work as common alarms: if any channel passes alarm limit, the relay activates. Device can be configured either with front panel keys or with serial interface using Mekuwin configuration software. Transmitter is compatible with WinX and PromoLog data-acquisition software and any third party software with Modbus communication. Modbus RTU or Noke val SCL protocol Digital inputs for selecting channel for analog output 16 channels 16 channels 16 channels 16 channels & -CL WinX or PromoLog Getting measurements from transmitters using serial communication is simple using either Nokeval SCL protocol or Modbus RTU, which is the only totally open de facto solution for industry. Multiplexing channels is an economical way to get measurement data for systems where it is not possible to get more analog inputs or serial communication. mA-outputs can be connected in parallel and only one device at a time is active. Active device/channel is selected by digital inputs. 1 analog output from any of the 256 channels (16 channels x 16 devices = 256 channels).

 Open the catalog to page 1
RMD680/RMD681-2

RTD sensors: Sensors Pt100, Pt1000 or Ptxxx (xxx = selectable) Measurement current 0,25 mA, multiplexed Sensor error correction Adjustable for each channel Serial interface: Connection Protocols Baud rate Bits Reaction time 16 channel read Maximum range Sensors Range Accuracy Sensors Range Sensor Range Ni100 or Nixx (xx = selectable) -60..+180°C 0.05% of reading + 0.25°C Cu10 or Cuxx (xx = selectable) -200..+260°C KTY83 -55..+175°C Alarms: 2 alarm relays, max 250VAC, 2A resistive General alarms selectable Thermocouples: Sensor Digital inputs: Analog output: Accuracy mA output load Reaction...

 Open the catalog to page 2

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*Prices are pre-tax. They exclude delivery charges and customs duties and do not include additional charges for installation or activation options. Prices are indicative only and may vary by country, with changes to the cost of raw materials and exchange rates.