13
KWE P
/N 3940
46 Ve
rsatronik
502 a
nd 502D
MODBUS G
atewa
y V1
.0 F
eb
2
014 Te
chni
ca
l i
nformation subj
ec
t to
ch
ange
w
ithout noti
ce
Connection Overview—120VAC
Communication connections—Vitocontrol-S, MW2 for Vitodens 200, WB2B
Modbus
145KMK
145KMK
Modbus
Connection
!
"
!
#
"
!
24VAC
4
Refer to manual specific to boiler
control. Ensure necessary LON
communication card installed.
1 A 3’/91cm CAT-5 cable is supplied
with the gateway. The RJ45 is
plugged into the control and
terminates into the RJ45 socket
inside of the Versatronik 502
gateway.
2 Versatronik 502 gateway.
3 Field wiring for Modbus connection
to terminals A and B.
4 Field supplied 24VAC power supply
for gateway.
Connection Overview
2
3
1
Modbus Wiring Connections (RS-485 Network)
COM 1 terminals A and B are used. It is to be
noted that the A/B naming convention may differ
across manufacturers.
A=(+) non-inverting
B=(—) inverting
Termination and Bias:
This device does not have a termination resistor
installed. There are two weak (4.7Kohm) pull up/
down resistors located on the lines to maintain a
bias.
Modbus Wiring Connections
