IBM DS-2000 warranty Output Configurations

OUTPUT CONFIGURATIONS

The other function of J2 and J3 is to configure the communication channel in half or full duplex mode. Half duplex operation is achieved by connecting pins 4 and 8 o f t h e j u m p e r b l o c k ( f i g u r e 2 3 ) . T h i s a l l o w s t h e transmitter to be enabled and disabled using the data t e r m i n a l r e a d y ( D T R ) o u t p u t i n t h e m o d e m c o n t r o l register. Full duplex operation is restored by removing the jumper on pins 4 and 8 (figures 21 and 22).

Jumper J4 selects the level of DTR that enables the transmitter outputs . When the enable control line is c o n n e c t e d t o + D T R ( f a c t o r y c o n f i g u r a t i o n ) , w r i t i n g a l o g i c 1 t o t h e D T R b i t l o c a t i o n i n t h e M O D E M c o n t r o l r e g i s t e r e n a b l e s t r a n s m i s s i o n . W r i t i n g a l o g i c 0 disables transmission . In this configuration, trans - mission is disabled on power-up.

Enable1

-DTR --+ +-- +DTR +-----------+

4 o o--o 6

J4 1 o o--o 3 +-----------+

-DTR --+ +-- +DTR

Enable2

To maintain compatibility with some other Quatech products, the enable control line can be connected to - DTR. In this configuration, writing a logic 0 to the DTR b i t l o c a t i o n i n t h e M O D E M c o n t r o l r e g i s t e r e n a b l e s transmission, logic 1 disables transmission . In this

configuration, transmission				is enabled on power-up.
			Enable1
	-DTR --+				+-- +DTR
		+-----------+
	4		o--o		o	6
J4	1		o--o		o	3
		+-----------+
	-DTR --+				+-- +DTR
			Enable2

CAUTION:

W h e n o p e r a t i n g i n h a l f d u p l e x m o d e , t h e transmitter must be disabled before receiving any information. Failure to do so will result in two output drivers being connected together w h i c h m a y c a u s e d a m a g e t o t h e D S - 2 0 0 0 , t h e computer and the peripheral equipment.

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