Honeywell 7800 - Manual (Page 5)

7800 SERIES S7810B MULTI-DROP SWITCH MODULE
5 65-0228—3
Fig. 2. Wiring S7810B Multi-Drop Switch Module.
QS7800B DATA
CONTROLBUS™
MODULE
A B C
1
2
3
4
5
6
7
7
7
6
5
5
5
5
5
5
3
3
3
3
2
2
2
1
1
4
4
8 7 6 5 4 3 2 1
S7810B MULTI-DROP
SWITCH MODULE
7800 SERIES
RELAY MODULE
8 7 6 5 4 3 2 1
S7810B MULTI-DROP
SWITCH MODULE
7800 SERIES
RELAY MODULE
8 7 6 5 4 3 2 1
S7810B MULTI-DROP
SWITCH MODULE
7800 SERIES
RELAY MODULE
INPUT
OUTPUT
+ –
GND
+ –
GND
1 2 3 4 5 A B C
MOMENTARY
PUSHBUTTON
SWITCH
S7800 REMOTE
KEYBOARD DISPLAY
MODULE
S7830 EXPANDED
ANNUNCIATOR
RS-485
REPEATER
8
8 TERMINAL NUMBERS ARE ON 203541 5-WIRE CONNECTOR (SUPPLIED WITH REMOTE MOUNTING BRACKET).
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 SHIELD, THE SHIELD END CLOSEST TO THE S7810B
MULTI-DROP SWITCH MODULE SHOULD BE ATTACHED TO EARTH GROUND. TO REDUCE INDUCTIVE INTERFERENCE (RF
INTERFERENCE), THE SHIELD SHOULD BE GROUNDED AT BOTH ENDS.
MULTI-DROP RS-485 COMMUNICATIONS BUS. UP TO 31 S7810B MULTI-DROP SWITCH MODULES (SUBNETWORKS) CAN BE
CONNECTED TO A SINGLE QS7800B CONTROLBUS™ MODULE WITHOUT AN RS-485 REPEATER. UP TO 61 S7810B MULTI-DROP
SWITCH MODULES (SUBNETWORKS) CAN BE CONNECTED TO A SINGLE QS7800B CONTROLBUS™ MODULE WITH AN RS-485
REPEATER. WHEN USING AN RS-485 REPEATER, THE REPEATER MUST BE INSTALLED BETWEEN THE 30TH AND 31ST SUBNETWORKS.
THE SUBNETWORKS MUST BE WIRED IN A DAISY CHAIN CONFIGURATION. RECOMMEND THAT THE QS7800B CONTROLBUS™
MODULE BE AT ONE END OF THE DAISY CHAIN.
MULTI-DROP COMMUNICTINS 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 QS7800B CONTROLBUS™ MODULE.
(IF INSTALLED AT ONE END OF DAISY CHAIN), INSTALL A 120 OHM, 1/4 WATT RESISTOR BETWEEN TERMINALS 7 AND 8 OF THE LAST
S7810B MULTI-DROP SWITCH MODULE IN THE DAISY CHAIN.
B. WITH RS-485 REPEATER: WHEN AN RS-485 REPEATER 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 QS7800B CONTROLBUS™ MODULE.
(IF INSTALLED AT ONE END OF 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 OUTPUT 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 S7810B
MULTI-DROP SWITCH MODULE IN THE SECOND DAISY CHAIN.
LOCAL RS-485 COMMUNICATION 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 OHM, 1/4 WATT, TERMINATION RESISTOR BETWEEN TERMINALS 1 AND 2 OR a AND b.
REFER TO QS7800B DATA CONTROLBUS™ MODULE INSTRUCTIONS, FORM 65-0227, FOR INSTALLATION INSTRUCTIONS.
THE MULTI-DROP BUS COMMON, S7810B TERMINAL 6, AND THE LOCAL BUS COMMON, S7810B TERMINAL 3, MUST NOT BE
ELECTRICALLY CONNECTED TOGETHER.
M11348C