Nokeval 6821 Programmable Dual-Channel Transmitter

The Nokeval 6821 is a rail-mounted two-channel measurement unit for temperature sensors and other electrical inputs. If needed the device can use inputs of different types on its channels. The unit has two analog outputs or alternatively the second output can be serial RS485 output. The device has up to four logical alarms with two alarm relays. Power supply is 90…240 VAC or 24 VDC.

There are four built-in inter-channel functions: average, difference, minimum, and maximum.

With MekuWin configuration software and simple Nokeval ELo-language, programs can be written to make the device calculate more mathematical and conditional operations and even timed events.


Writing your own functions

Measurement results and alarm states are written into registers. Users can easily write simple programs to modify registers F1-F12 (@18..29) using Nokeval’s ELo language and MekuWin configuration program. Any register can be used in the programs and as an output source.

How to write simple program?
The program consists of lines. Every line has one simple command. The command can change a register or cause a conditional jump inside the program. The program is entered in the configuration settings with Mekuwin.  Example: temperature input 1 controls output 1 together with input 2.

Flow sensor pressure compensation example
The mass flow rate can be easily calculated using the 6821 transmitter. Use channel 1 to mea­sure the flow, channel 2 to measure the pressure and write a small program using ELo language. For example, the program for the equation “Out1=(Ch1 x Ch2) x1.12/1000“ is found from programming examples.

Writing formula:

F2=In1*In2 // Channel 1 and 2 are multiplied, result in register F2
F1=F2*0.00112 // Register F1 = (Ch1 x Ch2) x 1.12/1000
Then the desired output is configured to follow the result, e.g. Outputs/Out1/Src = F1.


Input Details

Inputs: Pt100, Pt1000, KTY83, Thermocouples, mV, V, mA, Ohm
Input Channels: 2
Supply for Transmitters: +15V, 50mA
Measuring Rate: both channels 0.25s 

Output Details

Output Range: 0…20mA or smaller; 0…10V or smaller
Output Channels: 2
Outputs: mA, V
Output Loading: mA- 0…600 Ohm
Alarm Relays: 2

Connection Details

Connection Model: 25mm², detachable
Bus Interface: RS-485
Bus Protocol: Nokeval SCL; Modbus RTU
Baud Rates: 1200, 2400, 4800, 9600, 19200, 38400, 57600

Display Details

Display Colour: Red
Number of Digits: 4
Display: 7 segment LED
Digit Size: 7 mm
Indicator Lights: configuration state and alarms

Power Supply

Power Consumption: 24VDC-200mA; 240 VAC- 5W
Supply Voltage: 230 VAC: 85-260 V AC/DC

General Information

Weight: 250 g
Installation: 35mm DIN rail
Dimensions (WHD): 45x 100x 110mm
Minimum Ambient Temperature: -10°C
Maximum Ambient Temperature: 60°C
Case Material: Polyamide

Please call 01628 778688 for more information.