WAYJUN Hot products:WJ28 series 8 inputs channel Current/Voltage signal to RS485/232 Converter,24 Bits AD data acquisition,CE approved

4-20mA to RS485 Features:
>> Eight analog signal acquisition, isolated converter RS-485/232 output
>> 24-bit AD converter, accuracy>0.05%
>> 4-20mA/0-20mA current signal or 0-5V/0-10V voltage signal input
>> RS-485/232 interface can be programmed calibration module accuracy
>> Signal input / output:3000VDC isolation
>> Wide supply range: 8 ~ 32VDC
>> High reliability, easy programming, easy to apply
>> Standard DIN35 rail mounting
>> User-programmable settings module address, baud rate, etc.
>> Support the Modbus RTU protocol
>> Low cost, small size modular design
>> Size:120x60x43mm

Product List:

Selection Samples:
Part No.:WJ28-A4-485 (means 8 channels 4-20mA input,ouput is RS485 interface)
Part No.:WJ28-U1-232 (means 8 channels 0-5V input,output is RS232 interface)
Part No.:WJ28-U2-485 (means 8 channels 0-10V input,output is RS485 interface)
Part No.:WJ28-(A4)6(U2)2-485 (means 6 channels 4-20mA input,2 channels 0-10V input,output is RS485 interface)

How to set Modbus RTU communication protocol:

Module default protocol is character communications protocol. If you need to set the module to Modbus RTU protocol, please follow these settings:

1. Put INIT switch to INIT position.
2. Connect the power cord and the communication interface cable.
3. Turn on the power, the module enters the default state automatically, address 00, baud rate 9600.
4. Wait 5s, module is initialization.
5. Send the command $00P1(cr), check the response, if is !00 (cr), set successfully.
6. Turn off the power, INIT switch to the NORMAL position.
7. The module has been set to the Modbus RTU protocol mode successfully.

WJ28 analog signal acquisition module General parameters:

(typical @ +25 ℃, Vs to 24VDC)

Input type: Input current / voltage input

Accuracy: 0.05%

Temperature drift:± 30 ppm / ℃ (± 50 ppm / ℃, maximum)

Input Resistance: 50Ω (4-20mA/0-20mA/0- ± 20mA current input)

100Ω (0-10mA/0- ± 10mA current input)

1KΩ (0-1mA/0- ± 1mA current input)

>200K(5V/10V voltage input)

>1MΩ(below 2.5V voltage input)

Bandwidth: -3 dB 10 Hz

Conversion rate: 10 Sps

Common Mode Rejection (CMR): 120 dB (1kΩ Source Imbalance @ 50/60 Hz)

Normal Mode Rejection (NMR): 60 dB (1kΩ Source Imbalance @ 50/60 Hz)

Input Protection: over-voltage protection, over-current protection

Communication: RS-485 protocol or RS-232 standard characters protocols and MODBUS RTU communication protocol

Baud Rate (2400,4800,9600,19200,38400 bps) can be selected via software

Address (0 to 255) can be selected via software

Communication Response Time: 100 ms maximum

Power Supply: +8 ~ 32VDC wide range power supply, internal anti-reverse and over-voltage protection circuit

Power Loss: less than 1W

Operating Temperature: - 45 ~ +80 ℃

Humidity: 10 ~ 90% (no condensation)

Storage Temperature: - 45 ~ +80 ℃

Storage Humidity: 10 ~ 95% (no condensation)

Isolation Voltage: input / output: 3KVDC, 1 minute, leakage current:1mA

Which output signal and power supply are common ground.

Shock Voltage: 3KVAC, 1.2/50us (peak)

Dimensions: 120 mm x 70 mm x 43mm

Initialization WJ28 0-5V to RS485 modules:

All WJ28 modules, if you use RS-485 network, must be assigned a unique address code, address code value of hexadecimal numbers between 00 and FF. However, all new WJ28 module uses a factory initial settings, as follows:

Address code: 01

Baud rate: 9600 bps

Checksum is disable

As the new module address codes are the same, their address will be contradictory to other modules, so when you set up the system, you must reconfigure each WJ28 module address. WJ28 module can be connected the power cord and RS485 communication lines, through configuration commands to modify the WJ28 module address. Baud rate, parity and status, communication protocols also need to be adjusted according to user requirements. In the modified baud rate, parity and status, communication protocol, you must first enter the module to the default state, or can not be modified.

Register Description: (Common applications reading high 16-bit data to meet the accuracy requirements)

Table 5 Modbus RTU register description

more detail,please check this link: http://www.wayjun.net/index.php?main_page=product_info&cPath=3&products_id=43