Status Remote Reply (7Eh); Ack Reply (04H); Nak Reply (05H) - Sony HR Trinitron PVM-20M7MDE Interface Manual For Programmers

Command Description

Status Remote Reply (7EH)

The monitor returns the current remote status of the
monitor. The monitor always replies to the Status
Remote (6EH) command regardless of the actual
remote state.
The bit assignment is as follows.
Type of remote control
Control mode applied
Control mode applied
Remote mode = 01
Local mode = 10
Remote & Local mode = 11
Type of remote control
This value should always be 10 (serial).

ACK Reply (04H)

The monitor returns this command when the monitor
receives a command.

NAK Reply (05H)

The monitor retruns this command when an error
occurs in the serial communications.
When the monitor is in LOCAL mode, the monitor
returns the response to the Status Remote (6EH)
command. When the monitor receives a command
other than the Status Remote (6EH) command in
LOCAL mode, the monitor returns 0 corresponding to
the bit of undefined message of the NAK Replay
(05H).
Sony Corporation
Printed in Japan
The bit assignment is as follows.
Undefined message
Checksum error in received message
Parity error in received message
Overrun error in received message
Framing error in received message
Timeout error
Timeout error
When the time between bytes is less than 10ms, the
byte value is 0.
When the time between bytes exceeds 10ms, an error
occurs and the byte value is 1.
Framing error in received message
No error = 0
When the received message has a framing error =1
Overrun error in received message
No error = 0
When the received message has an overrun error = 1
Parity error in received message
No error = 0
When the received message has a parity error = 1
Checksum error in received message
No error = 0
When the received message has a checksum error = 1
Undefined message
When the monitor understands the received message =
0
When the monitor is in LOCAL mode and receives
this command, the monitor returns 0 for this item.
When the monitor does not understand the received
message = 1