9
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
1
Connection Overview—24VAC
Communication connections—Vitotronic 100, GC1 or 300, GW2
Modbus
Modbus communications
!
"
!
#
"
!
24VAC
5
Refer to manual specific to
boiler/system control. Ensure
necessary LON communication
card installed.
1 Control showing location of
LON card and its location
within.
2 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.
3 Versatronik 502 gateway.
4 Field wiring for Modbus
connection to terminals A
and B.
5 Field supplied 24VAC power
supply for gateway.
Connection Overview
2
4
3
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 re-
sistor installed. There are two weak
(4.7Kohm) pull up/down resistors located
on the lines to maintain a bias.
Modbus Wiring Connections