41-621.1 HART
®
to Modbus
®
Adaptor Operating Manual
23
be set to the range of 1 to 5 so that they correspond to the slave numbers shown in the
registers tables of Sections L through S.
8.3.2
Multiple HMAs
Install jumper wires connecting the positive terminal of the RS-485 terminal block of HMA1
and the positive terminal of the RS-485 terminal block of HMA2 as well as the negative
terminal of the two terminal blocks. Continue for the number of HMAs to be used on the
line. Connect a 120
resistor between the two RS-485 terminal block positions of the last
device on the RS485 line.
8.4.
Procedure
8.4.1
Connect the HMA to a power supply, Modbus host and MII HART transmitters as specified
in section 8.3.1.
8.4.2
Using Procedure 1, ensure that registers 3000 through 3007 of the HMA match the values
for the Modbus RTU protocol settings used by the intended Modbus master. 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.
8.4.3
Using Procedure 2, change register 3001 to a value of 15. This changes the address of the
HMA to 15 to be unique from other HMAs and from the attached devices. Note that the
choice of address for the HMA is not critical as long as it is different from other HMAs to
be used in the same system.
8.4.4
Change register 3007 to a value of 0. This sets the HMA to run in the HMA mode in which
only the HMAs are directly addressed by the Modbus master.
8.4.5
Change register 3013 to a value of 2. This will cause the HMA to scan poll addresses 0 to
15 for attached devices at start-up, and record the poll address and other information for
each device.
8.4.6
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.
8.4.7
Change DIP switch 1 to ON.
8.4.8
Change the slave ID for the Read/Write Definition from 247 to 15 (or the Modbus address
selected for the HMA).
8.4.9
Verify that register 3012 on each HMA has automatically changed to a value of 1
indicating that the HMA has found devices and stored their information in memory.
8.4.10
Verify that register 1250 on each HMA displays the correct number of attached devices.
Summary of Contents for Jupiter JM4
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