Black Box PCW22A-R4, PCW22A-R3 manual Nak

CHAPTER 4: Operation

Data Flow — A/S-2G to Synchronous Device

Bisynchronous Device A/S-2G Converter Asynchronous Device

If A/S-2G buffer is nearly full when asynchronous device is transmitting:

	X-OFF	Holds up transmission while
		buffer clears DC3 (ASCII 13
		Hex) or drop DTR CTS or
		user-specified lead
ACK 1	Send block C	Frees up buffer space.
		(Echo CR LF)
	X-ON	Allow resumption of
		transmission DC1 (ASCII 11
		Hex) or raise DTR

Complete block D

If data not properly received by synchronous device or

synchronous device has no WAK capability and buffer is full:

Send block D

NAK

Negative Acknowledgment

AA AA 32 32 32 32 3D FF FF

Resend block D

ACK 0

If synchronous device has WAK capability and buffer is full:

Send block E

(Echo all but CR LF)

Send block E

2-second interval

WAK

AA AA 32 32 32 32 6B FF FF

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