evertz 8010TM, Инструкция по эксплуатации

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Model 8010TM SDI Time Code Master Manual
SERIAL PROTOCOL
Revision 1.5.1
Page 4-3
R(STX)
SELECT
R (MESSAGE)
ERROR (Parity,checksum
undefined command, etc) TIMEOUT
(10 msec)
T(NAK)
T(STX)
T (MESSAGE)
T(ACK)
R (UNDEFINED)
R (BREAK)
T(ACK)
R(Enter Broadcast)
no response required
Broadcast
R(Enter Select) T(ACK)
Figure 4-1: Communications Protocol State Diagram
The communications protocol is described in Figure 4-1. The Evertz unit (Device) immediately enters
the select state upon power-up and remains there unless directed by an Enter Broadcast Cmd (02 hex)
to the broadcast communications state. The diagram shows the various states of the device. The
designation R( ) indicates the data received from the controller, while the designation T( ) indicates the
data transmitted by the Device.
4.3. MESSAGE BLOCK FORMAT
Once communications have been established, command messages may be sent to the Device.
Each control message starts with the STX character and ends with a checksum. The message blocks
are structured as follows:
STX BYTE COUNT MESSAGE CHECKSUM