JAZZ 20 Modbus RS485 connection to Unicloud
OZ
Ori Ziv
Oct-28th, 2024 10:12

Configuration Modbus -RS485 Parameters for Jazz unit – and connect to Unicloud with Modbus Slave connection type.

Use the example project I sent you and this is the explanation on every step of configuring the serial communication to RS485

Parameter

Store into SI

Function

Network ID

141

Range: 0-255.

This is the Network ID number of the device on the network. You can either assign an ID via an MI, or directly via a constant number. Do not assign the same ID number to more than one device

Time out

142

Time out units:10 msecs; a Time out value of 100 is equal to 1 second.
This is the amount of time a master device will wait for an answer from a slave.

Retries

143

This is the number of times a device will try to send a message.

Maximum Time Delay

144

Time units: 2.5 msec.
This is the maximum time interval permitted between 2 messages. This should be set to 2, setting the permitted interval to 5 msecs (n x 2.5 =interval).

Baud Rate

145

Store the value into SI 145 to set the baud rate.

Note that Jazz does not support the following baud rates: 110, 38400, 57600. In addition, ‘2’ Stop Bits is not supported. In Jazz controllers; use Function 310 to modify the default settings of an Add-on Port.

Legal Baud rates are:

110

300

600

1200

2400

4800

9600

19200

38400 (store 384)

57600 (store 57600)

Call MODBUS Configuration

140

This must be the final parameter stored.

Storing the value 600 into SI 140 configures the controller for MODBUS.

Storing the value 599 into SI 140 configures the controller for MODBUS and also enables Unitronics' PC applications to access the PLC.

After the parameters below have been stored into the appropriate SIs, initialize the COM port by storing 310 into SI 140.

SB 141 indicates whether the COM port has been successfully initialized with the new parameters successfully: 1 = success, 0 =fail.

Parameter

Store to SI

M91

Jazz: MJ20-RS

Jazz: MJ20-PRG

Baud Rate

141

Legal Baud rates
Store value into SI 141 to set baud rate.
  • 110
  • 300
  • 600
  • 1200
  • 2400
  • 4800
  • 9600
  • 19200
  • 38400 (store 384)
  • 57600 (store 576)
  • 300
  • 600
  • 1200
  • 2400
  • 4800
  • 9600
  • 19200
  • 300
  • 600
  • 1200
  • 2400
  • 4800
  • 9600

Data bits

142
  • 7
    8

Parity

143
  • 0=even
    1=odd
    2=none

Hardware Flow Control

144
  • 0=No Flow Control
  • 1=Flow Control

RS232:

  • 0=No Flow Control
  • 1=Flow Control
  • 2=enable RS485 and RS232

Note that in order to implement RS485, you must write 2 to SI144

Always write 0

Time out

145

Time out units:

  • secs; a Time out value of 100 is equal to 1 second. Legal values:
    50
    100
    150
    200
    500
    6000

Stop bits

146
  • 1
  • 2

2 stop bits is not supported

COM Init

140

This must be the final parameter stored.

Storing the value 310 into SI 140 initializes the COM port with the new parameters.

Second setting

Wiring procedure:

RS485 Connector Pinout


  • Pin 1: D_N (Driver negative signal)
  • Pin 2: R_N (Receiver negative signal)
  • Pin 3: GND (Device ground)
  • Pin 4: D_P (Driver positive signal)
  • Pin 5: R_P (Receiver positive signal)
  • Pin 6: NC (Not connected

Router parameters

Modbus commends to check connectivity first using the modbus serial master.

UniCloud

After you manage to made the connection with RS485 and read MI 10 for example, you need to connect device to Unicloud by “Modbus slave” connection type just follow the help files in Unicloud website/your organization.

Just follow the Unicloud section one by one and fill every thing like the guide tells you.

Mind that you are required to create Modbus slave serial number that will pop up like on the picture below:

Unicloud Help files for Modbus link:

https://unitronics.cloud/unicloud_help/#t=MODBUS.htm

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