47
7 OPTION
47
OPTION
Chapter
7
12 (0x0C) Get comm event log
This function is to read the event conditions from each slave.
The contents of status and event counter are the same as status 11 (Get comm event counter). The
message count is the same as subfunction 11 (Return bus message count) of status 08. As events, 64
byte conditions in which the slave receives and sends messages are held.
The most recent condition of events always comes at the 0th byte, and if 64 is exceeded, they are
discarded in the order of their occurrence.
The details of events will be defined later.
*N = Number of events + (3×2)
Example) Read the event conditions.
The example shows the event counter 264 (0x0108), message count 289 (0x0121), and not-busy
state (0x0000). The events indicate as follows: since the most recent condition of events is
11000000 (0xC0) and bit 6 is "1," broadcast has been received; and since the one-time-old event
is 00, the slave has received Communications restart.
[Request]
Function 1 byte 0x0C
[Response]
Function 1 byte 0x0C
Byte count 1 byte N *
Status 2
bytes 0x0000
Event counter 2
bytes 0x0000 - 0xFFFF
Message count 2
bytes 0x0000 - 0xFFFF
Event counter N bytes 0 - 64 (number of events)
[Error response]
Error code 1 byte 0x8C (function + 0x80)
Exception code 1
byte 01
[Request]
Function 0C
[Response]
Function 0C
Byte count 08
Status; higher 00
Status; lower 00
Event counter; higher 01
Event counter; lower 08
Message count; higher 01
Message count; lower 21
Event 0 C0
Event 1 00
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