Kramer Electronics Vertical Interval, Protocol Used for VS-1211/1201xl Communication, Where

14.7 Vertical Interval

Problem	Remedy
The switcher is switching, but there	There is no vertical interval Sync source for switching. It should be available
are transitional effects when using	either on video input #1 or on an external genlocked source as a live video or a
genlocked sources. The picture	live black burst signal. Which one, will depend on certain jumper settings.
jumps and rolls, and the color is lost	Turn OFF the power switch, remove the power cable from the mains socket and
until the acceptor (a VCR, for
	carefully remove the cover of the switcher. Carefully remove the audio board by
example) has readjusted itself to the
	unscrewing the four upper board screws. The upper board can now be raised with
new color information.
	ease. Find jumper J20 (also J34 in an interconnected configuration) and set up
	the Sync source in accordance with "Jumpers, Their Uses and Set-up
	Requirements" (see section 9.2).

15.PROTOCOL USED FOR VS-1211/1201xl COMMUNICATION

The protocol used for communication between the PC and the Master VS-1211/1201xl is defined as follows:

MSB							LSB
N7	N6	N5	N4	N3	N2	N1	N0

Where:

N7 is used for communication between the Slave and the Master only and is always 0 for communication with the PC.

N6N5N4 is the binary value of the Machine we are addressing minus one, e.g., if we wish to address the Master (Machine 1 by definition), then N6N5N4 = 000, if we wish to address Machine 6, then N6N5N4 = 101. N3N2N1N0 is the binary value of the input to be selected, i.e. N3N2N1N0 = 0111 is equivalent to pressing switch 7 on the front panel.

Several special codes are also valid:

N3N2N1N0 = 1101 requests that the Machine being addressed sends its present status to the PC, i.e. which input is selected on its front panel.

N3N2N1N0 = 1110 is an "OK" handshake, i.e. confirmation that the instruction was received by the addressed Machine. (If the addressed Machine is not present, then this confirmation is not sent to the PC).

Information sent from the Master to the PC is done using the same format, i.e.:

0	Machine Number -1	New Switch Status
N7	N6N5N4	N3N2N1N0

The rate of data transfer is always 9600 baud, with no parity, 8 data bits and 1 stop bit.

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