Contact closure
The contact closure port is used to monitor switches, sensors, or similar devices, and to trigger
events in response to changes to the monitored device. Insert the wires from the monitored
device into the contact closure port.
A 1k ohm pull‑up resistor in a TTL (5 VDC) circuit senses the contact closure.
•
When the external switch closes (shorts to ground, logic low) the port is on.
•
When the external switch opens (logic high) the port is off.
Connect two wires to the contact closure port, as shown in figure 11. If both the IR port and
contact closure port are used, the ground pin must be shared by both devices.
SG
IN
IR/C IN
Ground
Contact Closure Input
Switch,
Sensor
Figure 11.
Contact Closure Port
COM ports
The TLC has two COM ports, which support software flow control. They share a common
ground pin. Figure 12 shows how to wire a single port or both.
COM ports control and receive status messages from connected devices, using the following
RS‑232 protocols:
•
300 to 115200 baud (default = 9600 baud)
•
7 or 8 data bits (default = 8)
•
1 or 2 stop bits (default = 1)
•
No parity, even parity, or odd parity (default = no parity)
•
This port supports software flow control. The default is no flow control.
NOTE:
The maximum distance from the TLC to the device being controlled is usually
200 feet (61 meters), but this can vary, depending on factors such as cable gauge, baud
rates, environment, and output levels from the TLC or the device being controlled.
For bidirectional serial communication, the transmit, ground, and receive pins must be wired at
both the adapter and the device being controlled. For information about wiring the device being
controlled, see the user guide for that device.
If you use cable that has drain wire, the drain wire must be tied to ground at both ends. For best
results, insulate the common or drain wires using heat shrink.
Receive (Rx)
Transmit (Tx)
Transmit
COM 1 Rx
Receive
COM 1 Tx
G
Ground
1
Tx
Rx
Rx
G
Tx
COM1
RELA
YS
COM2
1
RELA
Y
S
IN
Tx
Rx
Rx
G
Tx
IR/C IN
COM1
COM2
IN
IR/C
IN
Transmit
COM 2 Rx
Receive
COM 2 Tx
Ground
Receive (Rx)
Transmit (Tx)
Ground
Device
controlled by
RS-232
Receive (Rx)
Transmit (Tx)
Transmit
Rx
Receive
Tx
G
Ground
Device 2
controlled by
RS-232
Device 1
controlled by
RS-232
Wiring a single COM port
Wiring both COM ports
Figure 12.
COM Ports
TLC Pro 526M, 726M, and 1026M Series TouchLink Pro Control Systems • Panel Features
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