Black Box IC133C-R2, IC187C manual Name Function

	CHAPTER 3: Card Setup
	Table 3-1. Jumper Operation
Name	Function
P	Adds or removes the 1K-ohm pull-down resistor in the
	RS-422/RS-485 receiver circuit (Receive data only).
T	Adds or removes the 120-ohm termination.
L	Connects the TX+ to RX+ for RS-485 two-wire operation.
L	Connects the TX- to RX- for RS-485 two-wire operation.

P

P

T

L

L

Figure 3-6. Headers J1A and J2A, which control line termination.

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