Data Video SE-2850, Руководство пользователя

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2.3.1.21. 022h — indication request instruction. The instruction in transmitted
without arguments. .The device status (6 bytes) is sent back in the response block
(see 3.) followed by the indication array. The structure of the indication array is
described in the Mandatory Annex 2 of the current Protocol. The LEDs codes are
listed in the recommended Annex 5 of the current Protocol;
2.3.1.22. 023h – device status request. The instruction in transmitted without
arguments. The device status is sent back in the response block (see 3.);
2.3.2. When a Slave sends response pack to the Master, the contents of the 1st
byte of the subblock must repeat the instruction byte of the control block which
began the transaction. The highest bit of the 2nd byte must be set as '1'. The lowest
3 bits of this byte must reflect the following status of the execution process of the
newly received instruction (i.e. the instruction which began the transaction):
00h — instruction has been executed. There are true data bytes in the response
block, if any;
01h – instruction has been accepted to the execution. There are no true data bytes in
the response block, if any. Ignore them;
02h — Device is busy executing the previous instruction. The newly accepted
instruction shall be ignored by the Slave in this state. There are no true data bytes in
the response block, if any. Ignore them;
03h — The Slave device is broken. There are no true data bytes in the response block,
if any. Ignore them;
04h – error in the format of the newly accepted instruction. There are no true data
bytes in the response block, if any. Ignore them;
Values 05h … 07h of the lowest 3 bits are reserved and are not used by the current
Protocol. The rest bits of this byte are reserved and must be set as '0'.
The ID subblock follows the address subblock.
2.4. The length subblock consists of 1 byte and it describes the length of the payload
subblock. Value 0 reports there is no payload subblock in the current block.
The length subblock follows the ID subblock.
2.5. The payload subblock is the only subblock which is not necessarily present in a
control block or a response block. The length of the payload subblock is 240
(decimal) bytes. Multibyte words are sent the lower byte ahead.
The payload subblock follows the length subblocks.