Product Overview

S7810M MODBUS™ MODULE
3 65-0249—07
Fig. 3. Wiring S7810M ModBus™ Module.
Wiring (Fig. 3)
1. Refer to Fig. 3 for proper wiring.
2. All wiring must comply with all applicable electrical
codes, ordinances and regulations.
3. Recommended wiring size and type:
a. For all communications, use 22 AWG, 3-wire shielded
cable (Belden part number 8723 or equivalent).
b. For 13 Vdc and remote reset switch operation, use
22 AWG wire insulated for voltages and tempera-
tures in the application. Suggested wire types
include TW (60°C), THW (75°C) and THHN (90°C).
Terminal identification numbers and letters are
shown in Table 1.
A
B
C
1
2
3
4
5
6
6
6
2
5
5
5
5
5
5
3
3
3
3
2
2
1
1
4
4
OUTPUT
+–
GND
7
7
PC/PLC
RS-485
BUS
MULTI-DROP RS-485 COMMUNICATION BUS. UP TO 31 S7810M MODBUS™ MODULES CAN BE CONNECTED TO A SINGLE BUS WITHOUT AN
RS-485 REPEATER. UP TO 99 S7810M MODBUS™ MODULES (SUBNETWORKS) CAN BE CONNECTED TO A BUS WITH RS-485 REPEATERS. WHEN
USING AN RS-485 REPEATER, THE REPEATER MUST BE INSTALLED EVERY 30TH MODULE.
THE SUBNETWORKS MUST BE WIRED IN A DAISY CHAIN CONFIGURATION. RECOMMEND THAT THE PC/PLC BE AT ONE END OF THE DAISY CHAIN.
LOCAL RS-485 COMMUNICATIONS BUS. THE DEVICES ON THIS BUS MUST BE WIRED IN A DAISY CHAIN CONFIGURATION. THE ORDER OF
INTERCONNECTION IS NOT IMPORTANT. THE MODULES ON THE CLOSEST AND FARTHEST ENDS OF THE DAISY CHAIN REQUIRE A
120 OM, 1/4 WATT TERMINATION RESISTOR BETWEEN TERMINALS 1 AND 2 OR A AND B.
THREE WIRE SHIELDED CABLE (BELDEN 8723 SHIELDED OR EQUIVALENT) IS RECOMMENDED AND SHOULD BE GROUNDED AS
FOLLOWS: IF NO INTERFERENCE IS PRESENT, OR TO REDUCE CAPACITIVE INTERFERENCE, THE SHIELD SHOULD BE GROUNDED
AT ONE END. WHEN GROUNDING ONLY ONE END OF THE THE SHIELD, THE SHIELD END CLOSEST TO THE S7810M MODBUS™
MODULE SHOULD BE ATTACHED TO EARTH GROUND. TO REDUCE INDUCTIVE INTERFERENCE (RF INTERFERENCE), THE SHIELD
SHOULD BE GROUNDED AT BOTH ENDS.
THE MODBUS™ BUS COMMON, S7810M MODBUS™ TEREMINAL 6, AND THE LOCAL BUS COMMON (S7810M MODBUS™ TERMINAL 3),
MUST NOT BE ELECTRICALLY CONNECTED TOGETHER.
TERMINAL NUMBERS ARE ON 203541 5-WIRE CONNECTOR (SUPPLIED WITH REMOTE MOUNTING BRACKET).
M23807
MODBUS™ COMMUNICATION BUS TERMINATION RESISTORS:
A. WITHOUT RS-485 REPEATER:
MODULES AT THE CLOSEST AND FARTHEST END OF THE DAISY CHAIN REQUIRE TERMINATION RESISTORS.
INSTALL A 120 OHM, 1/4 WATT RESISTOR BETWEEN TERMINALS A AND B OF THE PC/PLC (IF INSTALLED AT ONE END
THE DAISY CHAIN). INSTALL A 120 OHM, 1/4 WATT RESISTOR BETWEEN TERMINALS 7 AND 8 OF THE LAST S7810M MODBUS™
MODULE IN THE DAISY CHAIN.
B. WITH RS-485 REPEATER:
WHEN AN RS-485 REATER IS USED, TWO DAISY CHAIN CONFIGURATIONS ARE EFFECTIVELY FORMED. MODULES AT THE
CLOSEST AND FARTHEST ENDS OF EACH DAISY CHAIN REQUIRE TERMINATION RESISTORS. INSTALL A 120 OHM, 1/4 WATT
RESISTOR BETWEEN TERMINALS A AND B OF THE PC/PLC (IF INSTALLED AT THE END OF THE DAISY CHAIN. INSTALL A 120
OHM, 1/4 WATT RESISTOR BETWEEN INPUT TERMINALS DATA+ AND DATA- OF THE RS-485 REPEATER. INSTALL A 120 OHM,
1/4 WATT RESISTOR BETWEEN TERMINALS 7 AND 8 OF THE LAST S7810M MODBUS™ MODULE IN THE ADDITIONAL DAISY CHAIN.
MOMENTARY
PUSHBUTTON
SWITCH
S7810M MODBUS™
MODULE
8 7 6 5 4 3 2 1
7800 SERIES
RELAY MODULE
S7800 REMOTE
KEYBOARD
DISPLAY
MODULE
1 2 3 4 5
1 2 3 4 5
S7830
EXPANDED
ANNUNCIATOR
A B C
R7999
CONTROLINKS™
CONTROLLER
A B C
RS-485
REPEATER
INPUT
+
-
GND
S7810M MODBUS™
MODULE
7800 SERIES
RELAY MODULE
8 7 6 5 4 3 2 1
S7800
SERIES 5
7800 SERIES
RELAY MODULE
L1
L2
13 VDC
POWER SUPPLY