Carrier 48TC*D08 appendix Modbus, Manufacture Date, Basic Protocol Troubleshooting

48TC

Table 24 – Manufacture Date

When troubleshooting, you may need to know a control module’s manufacture date

Obtain the manufacture date from	Notes
a...
Module status report (modstat)	To obtain a modstat with BACview6:
	1. Press Function (FN) key and hold.
	2. Then press period (.)
	3. Release both buttons.
	The report shows the date under Main board hardware.
Sticker on the back of the main control	The serial numbers are unique and contain embedded information:
module board	“RMP”	--- These first three digits are unique to RTU--- MP and are used as an identifier.
”Serial No: RMPYMxxxxN”	“YM”	--- These two digits identify the last digit of the year and month (in hex, A=10/Oct)
(Bar Coded & Typed Number)	“xxxx”	of manufacture. ”74” would represent a date of manufacture of ”April 2007”.
		--- These four digits represent the sequential number of units produced for a given
	“N”	product for the mentioned manufacturing time period.
		--- This final digit represents the decade and toggles between ”N” and ”M” every
		ten years.

Table 25 – Basic Protocol Troubleshooting

Problem	Possible cause	Corrective action
No communication with 3rd	Incorrect settings on SW1, SW2 and SW3	Verify and correct switch settings. Cycle
party vendor		power to RTU--- MP after changing switch
		settings.
	RS485 Port has no voltage output	Verify RTU--- MP has correct power supply
	(check with RTU--- MP disconnected from RS485	Possible bad driver on board.
	communication bus)
	Bacnet @ 9600/19.2K --- .01 to .045vdc	Check RS485 bus for external before
		reconnecting to the bus
	Bacnet @ 38.4K --- .06 to .09vdc	Voltage, shorts or grounding
	Bacnet @ 76.8K --- .1vdc	before reconnecting to the bus
	Modbus @ 9600 --- 76.8K --- .124vdc
	N2 @ 9600 --- .124vdc
	Verify devices are daisy chained and repeaters and bias	Check 3rd party vendor RS485
	terminators are correctly installed	communication wiring guidelines and
		troubleshooting procedures

Table 26 – Modbus Exception Codes that May be

Returned From This Controller

CODE	NAME	MEANING
		The Modbus function code used
01	Illegal Function	in the query is not supported by
		the controller.
		The register address used in the
02	Illegal Data Address	query is not supported by the
		controller.
		The Modbus Master has
		attempted to write to a
04	Slave Device Failure	non--- existent register or a
		read--- only register in the
		controller.

Modbus

1.Verify that the BAS and controller are both set to speak the Modbus RTU protocol. The protocol of the controller is set via SW3 (switches 3, 4, 5, and 6). The protocol can also be verified by getting a Modstat of the controller through the BACview. Hit the ”FN” key and the ’.’ key at the same time to pull up a Modstat. Scroll to the bottom of the page and there is a section entitled “Network Communications.” The active protocol and baud rate will be shown in this section.

2.Verify that the BAS and controller are set for the same baud rate. The baud rate of the controller is set via SW3 (switches 1 and 2). The baud rate can also be verified via the BACview by obtaining a Modstat (see Fig. 70).

3.Verify that the BAS is configured to speak 2-wire EIA-485 to the controller. The BAS may have to configure jumper or DIP switches on their end.

4.Verify that the BAS and the controller have the same communication settings (8 data bits, No Parity, and 1 stop bit).

5.Verify that the controller has a unique Modbus slave address. The controller’s Modbus slave address is set by its rotary address switches.

6.Verify that the BAS is using the proper Modbus function codes to access data from our controller. Supported function codes are shown above.

7.Verify proper wiring between the BAS and the controller.

8.Verify that the BAS is reading or writing to the proper Modbus register numbers on the controller. Download the latest points list for the controller to verify.

9.Verify that the BAS is sending his requests to the proper slave address of our controller.

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