Specifications

Application Guide • BALTIC - 0108 • 67 •
ELECTRICAL DATA
CONTROL VARIABLES
Lennox Climatic 50 and BMS
Modbus, Trend or BACnet.
Specication of the Bus:
Type:
 RS485
Speed:(AdjustableonClimatic50viadisplayDS50;Setting3933)
 1200
 2400
 4800
 9600
 19200
Parity: Fixed
 noparity(N)
Length: Fixed
 8bits(8)
Stop bit: Fixed
 2bits(2)
Spécication du protocole:
Mode: Fixed
 R.T.U. for Modbus
Addressofslave:(AdjustableonClimatic50viadisplayDS50;Setting3931)
 1
 to 200
Supported functions, for Modbus:
 Reading Bits : 1 or 2
 Reading Words : 3 or 4
 Writing simple Bit : 5
 Writing simple Word : 6
Functionality `Watchdog’ on Climatic 50.
The automat Climatic 50 being passive on the bus it cannot detect any cut of communication with the BMS. From where in the
eventofcutofcommunicationtheRoof-TopwouldcontinuetofunctionwiththelastadjustmentsemittedbytheBMS.Toavoidope-
ration, penalizing the correct operation of the Roof-Top, the BMS must regularly write in the word 01h a value different from 0. The
automat Climatic 50 decreases the value of the word 01h of 5 units every 5 seconds.
If the BMS writes the value 1000 in the word 01h, in the event of cut of communication at the end of 16 minutes 40 seconds the
instructions emitted by the BMS are not taken more into account by the software of the automat Climatic 50. I.e. the following points
are not took into account by the program of the automat Climatic 50 if the word 01h is equal to 0
Points concerned with the word 01h
Words :
 02H/03H/04H/05H/06H/07H/08H
Bits :
 03H / 04H / 06H / 07H / 08H / 09H / 0AH / 0BH / 0CH / 0DH / 0EH
This functionality does not prohibit the writing of the bit or of the word, those are always readable on our display DS50 (show in
modeBMSviathekey`Prg’)