[email protected] www.nokeval.com 6821 Programmable dual-channel transmitter • 2 analog inputs, 0/4..20 mA or 0..5/10V, mV, Pt100, thermocouples • 2 analog outputs 0/4..20 mA or 0..5/10V • 2 alarm relays • Mathematical and conditional operations using easy logic language (ELo) • Serial communication RS-485 • Modbus RTU and Nokeval SCL protocols • Power supply 90..240 VAC or 24 VDC • Conguration using MekuWin PC program or using front panel buttons 6821 is a rail-mounted two-channel measurement unit for temperature sensors and other electrical inputs. The unit has two analog outputs or alternatively one analog and one serial output. The serial output can accept Nokeval SCL and Modbus RTU commands. Up to four logical alarms can control two common alarm relays. The inputs are galvanically isolated from the outputs and the supply voltage, but not from each other. Mathematical and conditional operations may be realized with a simple programming language. There is a four-digit display and four pushbuttons, that can be used to monitor the readings and to change the settings. The settings can also be edited from a personal computer using the RS-485 serial connection. Schematic drawing of transmitter 6821 Inputs: • Pt100, Pt1000, Ni100, KTY83, Cu10 • Thermocouples: B, C, D, E, G, J, K, L, N, R, S, T • mV inputs: ±55 mV, ±100 mV • 0..20 mA, 4..20 mA, ±20 mA 0..1 V, ±1 V, 0..10 V, ±10 V • Resistance measurement: 0..400, 0..4 kΩ, 0..40 kΩ Galvanic isolation Built-in functions Avg Min Max Diff User program Writing your own functions Measurement results and alarm states are written into registers. Users can easily write simple programs to modify registers F1-F12 using Nokeval’s ELo language and MekuWin conguration program. Any register can be used in the programs and used as an output source. Flow sensor pressure compensation example Serial connection Nokeval SCL Modbus RTU 2 alarm relays: max. 240 VAC, 2A Four separate logical alarms can be set Programming examples using ELo language (MekuWin) Input channels 1 and 2 correspond to registers @1 and @2, any register can be used as an output source. Channels multiplied @18=@1*@2 // The result is placed in register 18 (F1) Mass ow rate can be easily calculated using 6821 transmitter. Use channel 1 to measure the ow, 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. // If current rdg is smaller, skip the next line // Store the new peak in register 18 (F1) // Register 18 (F1) will indicate seconds // Channels multiplied, result in register 19 (F2) // Register 18 = (Ch1 x Ch2) x 1.12/1000

Technical specication Voltage Inputs Ranges RTD Inputs Pt100 Range Accuracy Same as meas. cycle + denable delay Relays 2 A, 250 VAC Device unpowered Relay 1 open, 2 closed. A/D conversion Speed Warm-up time 16 bits (±32767) All channels in 0.25 sec. 30 min (Tc inputs), 5 min (other inputs) Transmitter supply: +15 V 50 mA (if 4-wire connection on input 2 is not used) Analog outputs mA output Range Accuracy Load Thermal drift 0.02°C / °C (ref 25°C) 0.05% rdg + 0.5°C + lin. error + thermal drift ±55 and ±100 mV 0.1% rdg + 0.01 mV >1 MΩ Accuracy Load PtXXX, NiXXX, CuXXX Range Same as Pt100, Ni100...