TEXIO PW16-2ATP, Инструкция по эксплуатации, Страница: 70 / 86

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9-5-3. Status bytes
・
When a slave unit issues a message, the master unit receiving it sets the following status byte
according to the message.
Message from slave units Status byte
CC message 41H
MS message 42H
UU message 43H
Other message 50H
If a single statement contains several messages, the status byte is that of the first message.
<Example 9> The status byte is 50H when a message from the slave unit is PWID...; ST0....
9-5-4. Application configuration
・
Create an application in the sequence shown below when using the service request function using
the IF-41GU/IF-41USB or sending a command requiring a response message.
（
Descriptions
）
・
Monitor the status byte at all times. Receive a message to the local bus master. The local bus
master may store a maximum of 32 messages. Data is overwritten from older one if no message
is received.
・
Before sending a message, monitor the status byte and make sure that the PW-A units send no
messages.
・
When a command requiring a response message is received, the time until returning a message
or the order of response messages to the message sent by the local bus master may change.
Check the status byte to see if a message is present or absent. Be sure to interpret the
message header and address when interpreting a message.
Fig.28 Flow Chart when Receiving Message from PW-A Power Supply Unit
Processing including
command transmission
Checking
the status byte
Receiving
the message
Interpreting
the message
Processing according
to the message
No message present Message present
Reading
the status byte
Start