3
Input Connections
The following sections describe the input connections that can be made to the
KMDigital input side of the interface. See the site plan wiring diagrams for specific
requirements.
RS-232 (EIA-232) Inputs
RS-232 inputs are connected to the terminal in the upper left corner of the inter-
face.
Detail
As a general rule in RS-232 wiring, the Red lead is the Receive (Rx) lead and the
Black wire is the Transmit (Tx) lead.
Connect the appropriate leads to the indicated connectors on the terminal.
RS-485 (EIA-485) Inputs
Make connections to a network using the RS-485 connector.
Detail
An End-of-Line connection will have only one wire attached to the A and B termi-
nals. See
EOL (End Of Line) Setting on page 5
for EOL switch setting.
◆
Use 18 gauge, twisted-pair, shielded cable with capacitance of no more than
about 50 picofarads per foot for all network wiring. Belden cable model #82760
meets KMC requirements.
◆
Connect the nodes of the network in a daisy-chain arrangement. This means
connecting the
A
terminal in parallel with all other
A
terminals and connecting
the
B
terminal in parallel with all other
B
terminals.
◆
Connect the shields of the cable together at each controller.
◆
Connect the shields to an earth ground
only at one end of the segment
; tape
back the shield ground at the other end.
Illustration 2—Mounting Hole Locations
KMD-5540 CommTalk Protocol Interface Installation & Operation Guide
Installation
GND
~
GND
A1
B1
LAMPS
RDY
COM
PWR
24VAC
GND
TX1
RX1
GND
A2
B2
COM
RDY
LAMPS
GND
RX2
TX2
OFF
ON
ON
OFF
6.0"
4.0"
