41-621.1 HART
®
to Modbus
®
Adaptor Operating Manual
51
15.
HMA Diagnostics
15.1.
Purpose
This procedure instructs how to configure the HART to Modbus Adaptor (HMA) to display diagnostic
information. While the default Modbus RTU protocol is used to communicate with the HMA in this
procedure, any supported Modbus RTU or ASCII communication configuration can be used.
15.2.
Equipment
Item
Manufacturer
Model
HART to Modbus Adaptor
MII
031-2859-001
RS485 Communications cable
FDTIchip
USB-RS485-WE
Termination resistor
-
120
Modbus host application
www.modbustools.com
Modbus Poll
Power Supply
-
20-24V, 0.5A
Level transmitter
MII
Model 706
Probe
MII
Model 706 compatible
15.3.
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. Connect up to five Magnetrol HART level
transmitters (including the transmitter in the housing containing the HMA) to the HART loop terminal
block of the HMA.
15.4.
Procedure
15.4.1
Using Procedure 1, ensure that registers 3000 through 3007 of the HMA match the values
shown for the Modbus RTU protocol default settings. Refer to Appendix F for the HMA
Communication settings. If the settings do not match, double-click on a value that needs
to be changed to open the Write Single Register dialog, enter the new value, and then
click on Send.
15.4.2
Change register 3012 to a value of 0. This will cause the HMA to scan the attached
devices at start-up, and record the poll address and other information for each device.
15.4.3
Power cycle the HMA, or move DIP switch 1 to ON and then back to OFF.
Содержание Jupiter JM4
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