Magnetrol Jupiter JM4, Operating Manual

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41-621.1 HART ® to Modbus ® Adaptor Operating Manual
2.
Reading and writing registers in the HMA
2.1.
Purpose
This procedure instructs how to read and write HART to Modbus Adaptor (HMA) registers using a basic
Modbus master simulator application. The procedure can also be performed using any Modbus master
that permits reading and writing of the appropriate registers in the HMA.
2.2.
Equipment
Item Manufacturer Model
HART to Modbus Adaptor MII 031-2859-001
USB Communications cable FDTIchip USB-RS485-WE
Termination resistor -
120

Modbus host application www.modbustools.com Modbus Poll
Power Supply - 20-24V, 0.5A
2.3.
Setup
Connect the HMA to a power supply via the power terminal block. Connect an RS-485 communications
cable to the RS-485 terminal block of the HMA, with the Receive/Transmit Data+ A lead (orange) on
the positive terminal and the Receive/Transmit Data
– B lead (yellow) on the negative terminal.
Connect a 120

resistor between the two RS-485 terminal block positions. Connect the other end of
the cable to a PC which has a Modbus host application.
2.4.
Procedure
2.4.1
Ensure that the DIP switches on the HMA are set to 1 == OFF (Default Config Mode), 2 ==
OFF, 3 == OFF, 4 == ON. See Appendix A for the location of the DIP switch, and Appendix
B for a legend of the four switch positions.
2.4.2
Open the Modbus Poll application.