Patton electronic 1004ABRC user manual S3-1 Receive Impedance, S3-2 RTS/CTS Delay, S3-3 Reserved

S3-1: Receive Impedance

The setting for switch S3-1 selects the impedance of the input receiver. You may select either a “low” impedance of 120 Ohms or a “high” impedance of 16K Ohms. By selecting the proper impedance for each drop, there may be up to 50 receivers in one application.

S3-1	Setting
On	Low (120 Ohm)
Off	High (16K Ohm typical)

S3-2: RTS/CTS Delay

The setting for switch S3-2 determines the amount of delay between the time the Model 1004ABRC “sees” RTS and when it turns on CTS. Note: RTS/CTS Delay setting should be based upon trans- mission timing.

S3-2	Setting
On	8 msec
Off	no delay

S3-3: Reserved

Switch S3-3 is reserved and must remain in the OFF position.

S3-3	Setting
On	Not a Valid Setting
Off	Default Setting

S3-4: Echo Mode

The setting for switch S3-4 determines whether the Model 1004ABRC echoes data back to the transmitting device (half-duplex mode only).

S3-4	Setting
On	Echo On
Off	Echo Off

SWITCH SET “S4”

DIP switch S4 is used to configure transmit impedance, and 2-wire/4-wire operations. The summary table below shows the factory default settings for switch S4. Following the summary table is a detailed description of each individual switch.

SWITCH S4 SUMMARY TABLE (factory defaults in bold)

Position	Function	ON Position	OFF Position
S4-1*	TX Impedance	Intermediate	High
S4-2*	TX Impedance	Intermediate	High
S4-3*	2-Wire/4-Wire	2-Wire	4-Wire
S4-4*	2-Wire/4-Wire	2-Wire	4-Wire

*Note: Switches S4-1 and S4-2 must be switched simultaneously. Switches S4-3 and S4-4 must be switched simultaneously.

S4-1 and S4-2: “Transmit Off” Impedance

Switches S4-1 and S4-2 are set together to determine whether the receiving device “sees” the impedance of the Model 1004ABRC’s trans- mitter as being “high” or “intermediate” when the transmitter is turned off. The “intermediate” setting is useful in half-duplex environments where the receiving device does not respond well to the “high” setting.

S4-1	S4-2	Setting
On	On	Intermediate Impedance
Off	Off	High Impedance

S4-3 and S4-4: 2-wire/4-wire Modes

Switches S4-3 and S4-4 are set together to determine whether the Model 1004ABRC is in 2-wire or 4-wire operating mode. Note: 2-wire mode is half-duplex only.

S4-2	S4-3	Setting
On	On	2-wire mode
Off	Off	4-wire mode

9 10