41-621.1 HART
®
to Modbus
®
Adaptor Operating Manual
93
19.
ThermoScientific AutoPILOT PRO
–
Modbus RTU / ASCII
The following procedure applies to operation with both RTU and ASCII communication. The choice of
communication protocol is made in step 19.1.1 for the HMA settings, and step 19.4.5. The Modbus
RTU protocol is used for the following.
19.1.
Initial HMA Configuration
19.1.1
Using Procedure 1, ensure that registers 3000 through 3007 of the HMA match the values
shown for RTU communication with the AutoPILOT PRO. 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.
19.2.
Physical Connections
19.2.1
Connect the AutoPILOT PRO to a computer using a CHIT computer connection cable
(ThermoScientific p/n 3-0446-090).
19.2.2
Connect an appropriate 12 VDC power supply to the terminals of TB-1 on the inside of the
AutoPILOT PRO front panel.
19.2.3
Connect an RS-485 communications cable between the terminals of TB-16 of the
AutoPILOT PRO and the RS-485 terminal block (TB2) of the HMA. The
‘
+
’
terminal of the
HMA should be connected to the TX+ terminal of TB-16. The
‘
-
‘
terminal of the HMA
should be connected to the TX- terminal of TB-16.
19.2.4
On the main board of the AutoPILOT PRO, add a jumper to pins 15-16 of J39 to select 2-
wire mode.
19.2.5
On the main board of the AutoPILOT PRO, add a jumper to J40 to select RS-485 mode.
19.2.6
Connect a 120
resistor between the two RS-485 terminal block (TB2) positions of the
last HMA on the bus.
Summary of Contents for Jupiter JM4
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