Bacnet, Modbus, N2, And Yorktalk 2 Communications - York YLAA0041 Installation Operation & Maintenance

Section 7: Unit controls
BACnet, Modbus, N2, and Yorktalk 2
communications
Data can be read and in some cases modified using a
serial communication BACnet, Modbus, or YorkTalk
2 network connection. This information allows com-
munications of chiller operating parameters and exter-
nal control changes to setpoint, load limiting, and start/
stop commands.
BACnet and YorkTalk 2 RS485 networks are wired to
the + and - terminals of TB1 for port 1 communica-
tions. Modbus network connection has the option of
RS232 or RS485 connection for port 2 communica-
tions. Modbus network is wired to either TB2 or TB3
as follows:
DE MODIFIER ADDRESS
DE MODIFIER OFFSET
P1 PROTOCOL
P1 MANUAL MAC
ADDRESS
P1 BAUD RATE
P1 PARITY
P1 STOP BITS
170
See Figure 47 on page 171 for TB1, TB2 and TB3
locations.
In most cases, communication parameters will need to
be modified. Table 30 on page 172 lists setup parame-
ters for the available protocols. Modification is accom-
plished by pressing the PROGRAM, DOWN ARROW,
DOWN ARROW, DOWN ARROW, DOWN ARROW,
and ENTER keys in sequence. The list below shows
the displays for the values that may be modified:
P2 PROTOCOL
XXXXX
P2 MANUAL MAC
ADDRESS
XX
P2 BAUD RATE
XXXXXX
P2 PARITY
XXX
P2 STOP BITS
XXXXX
P2 HW SELECT BIT
XXXXX
REAL TIME ERROR
RESET 1 = YES, 0 = NO 0
X
Note: See Table 22 on page 173 for error descriptions
• RS-485: connect to TB2 - Network (-1) to TB2
(-1); Network (+1) to TB2 (+1)
• RS-232: connect to TB3 - Network (RX) to TB3
(TXD); Network (TX) to TB3 (RXD); Network
(GND) to TB3 (GND)
XXXXXXXXXX
XXX
XXXXX
XXXXX
X
XXXXX
##
Form 150.72-ICOM6
Issue date: 12/19/2023
Johnson Controls