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Structure and functions
14
Building Technologies
048_DMS_NK8237_ICC_MP4.40_A6V10316241_a_en.doc
Fire Safety & Security Products
06.2011
Fig. 5 NK823x internal DIP switch and jumpers (NKM8001-A2 mainboard)
4.1.4
Serial interfaces
The NK8237 is equipped with two serial lines available on the NK823x main board.
The serial port can be configured as an RS232 interface using connector COM1
and COM2, or as an RS485 interface using connectors X104 and X105.
All lines are fully RS232 compliant and have EMC/ESD protection.
No galvanic isolation is provided; all serial lines have a common ground.
4.1.5
Onboard I/O
The NK823x main board is equipped with three digital inputs (X102) and one relay
output (X101).
The relay output can be used for reporting a faulty communication detected by a
watchdog timeout expiration (see 7.7.1 at p.45).
X101 onboard relay output
Pin Signal
Circuit
1 Common
2 NO
3 NC
The input signals can be used for acquiring external power supply supervision
lines, e.g. for the supervision of the fire system power supply. Note that this is al-
ternative to the DF8090 power supply supervision described below).
X111
X104
X3
X103
S2: Tamper switch
S1: Reset button
X2
X1
X101
X102
X105
S101: DIP-Switches