AERCO Modulex E8 Controls Guide - Manual (Page 72)

PR1: 11/30/12 Page 72 of 112
GF-115-C Modulex E8 Controller and BCM
Operations and Maintenance Manual
OMM-0084_0D
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526- 0288
Figure
7-
11
.
EMS
/BAS Master Controlling Modulex Boiler Slaves
TO OTHER NETWORK BOILER SLAVES
(3
- 9
)
(SEE NOTE
3)
EMS MASTER
T+/
R
+
T-
/R
-
RS485 PORT
SHIELD
+
Y
2-
2
– MODBUS “A”
(-
)
(PART OF BCM CONN
. Y
2)
MODULEX BOILER SLAVE
#1
NOTES
:
1.
IF EMS MASTER CONTAINS A
4-
WIRE RS
485
PORT
,
TIE THE TWO POSITIVE
(+)
AND NEGATIVE
(-
)
LEADS TOGETHER AS SHOWN IN DETAIL “A” 2.
IF EMS MASTER CONTAINS ONLY A RS
232
PORT
, A RS
232
-TO
-RS
485
CONVERTER WILL BE
REQUIRED
.
3.
THE LAST BCM SLAVE ON THE RS
485
LOOP
MUST HAVE ITS TERMINATION RESISTOR ENABLED
.
ALSO
,
A
1K OHM BIAS RESISTOR
MAY BE REQUIRED
.
CHECK WITH THE EMS
MANUFACTURER
.
SEE NOTES
1
&
2
DETAIL “A” (SEE NOTE
1)
T+ T-
4-WIRE RS 485 PORT SHIELD
R
+
R
-
T+/
R
+
T-
/R
-
Y
2-
1
– MODBUS “B”
(+)
BCM
+
Y
2-
2
– MODBUS “A”
(-
)
(PART OF BCM CONN
. Y
2)
MODULEX BOILER SLAVE
#2
Y
2-
1
– MODBUS “B”
(+)
BCM
Fi
gur
e
7-
11
: