AERCO Modbus Communications Manual - Manual (Page 71)

Chapter 4
MODBUS
Communication GF-114
Hardware Setup & Installation USER MANUAL OMM-0035_0C
05/18/12 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 71 of 200
EMS
MASTER
RS485 PORT
T
+/
R
+
T
-/
R
-
SHIELD
BMS
RS232 PORT
Tx Rx
GND
J2P PWM TERMINALS
+ +
- -
BMS IN BMS IN
P
/O I
/O BOX
P
/O I
/O BOX
C
-MORE
LEGACY BOILER
1
LEGACY BOILER
8
BLR
1
BLR
8
- - - - - - -
C
-MORE
- - -
NOTES
:
1.
IF EMS MASTER CONTAINS
4-
WIRE RS
485
PORT
,
TIE THE TWO POSITIVE
(+)
AND NEGATIVE
(-
)
LEADS TOGETHER AS SHOWN IN DETAIL “A” 2.
RS
485
-TO
-RS
232
CONVERTER NOT REQUIRED
IF EMS MASTER CONTAINS RS
232
PORT
.
EMS
CAN BE DIRECTLY CONNECTED TO BMS
.
(SEE NOTE
1)
T
+
T
-
SHIELD
R
+
R
-
T
+/
R
+
T
-/
R
-
DETAIL “A”
4-WIRE RS 485
Figure
4-
11
.
EMS Master Controlling BMS Slave
RS
485 TO
RS
232
CONVERTER
(SEE NOTE
2)