Mitsubishi F940GOT-LWD-E, Руководство по эксплуатации

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Graphic Operation Terminal F940GOT Introduction 1
1-22
• Communication procedure
In communication between the GOT and the host unit, the host unit sends a command, and
the GOT sends back a response. While the GOT is sending the response to the host unit,
the GOT cannot receive new commands.
When an error occurs, the GOT sends back a NAK code as a response. The contents of the
error can be checked by reading a special memory.
As an exception, when the GOT gives a notification for interrupt, the GOT sends an interrupt
code. However, while the GOT is sending a response, it does not sends an interrupt code. In
such a case, immediately after sending a response, the GOT sends an interrupt code. The
GOT may send an interrupt code while receiving a command.
When an event such as change in the ON/OFF status of a specific bit and screen change
over has occurred, the GOT sends an interrupt code. The table below shows the correspon-
dence between the interrupt code and the event type.
Event type
Interrupt code
(hexadecimal)
M8000 is changed to ON.
M8000 is changed to OFF. 50
51
M8000 is changed to ON.
M8000 is changed to OFF. 52
53
.
.
.
M8000 is changed to ON.
M8000 is changed to OFF. 7E
7F
.
.
.
M8000 is changed to ON.
M8000 is changed to OFF. B2
B3
The display screen is changed
over.
20
Input of a numeric is com-
pleted.
21
Transfer of a data file is com-
pleted.
22
Host unit
GOT
Command
Response
Command
Response
Command
Response
Interrupt
Host unit
GOT