A communication check can be made because the query message that was sent is returned
unchanged as a response message (function of subfunction code H00).
Table 1. Query Message
| Subordinate Address |
Function |
Subfunction |
Date |
CRC Check |
| (8
bit) |
H08 (8
bit) |
H00 (8
bit) |
H00 (8
bit) |
H (8
bit) |
L (8
bit) |
L (8
bit) |
H (8
bit) |
Table 2. Normal Response (Response Message)
| Subordinate Address |
Function |
Subfunction |
Date |
CRC Check |
| (8
bit) |
H08 (8
bit) |
H00 (8
bit) |
H00 (8
bit) |
H (8
bit) |
L (8
bit) |
L (8
bit) |
H (8
bit) |
Table 3. Query Message Setting
| Message |
Setting
Description |
| Subordinate Address |
Address
to which the message is sent. Broadcast communication cannot be made: 0
is an invalid setting. |
| Function |
Set
H08 |
| Subfunction |
Set
H000 |
| Data |
Any data
can be set if it is 2 bytes long. The setting range is H0000 to
HFFFF. |
Table 4.
Normal Response Message to Query1
| Message |
Setting
Description |
| Subordinate Address |
Address
to which the message is sent. Broadcast communication cannot be made: 0
is an invalid setting. |
| Function |
Set
H08 |
| Subfunction |
Set
H000 |
| Data |
Any data
can be set if it is 2 bytes long. The setting range is H0000 to
HFFFF. |
For broadcast communication, no response is returned in reply to a query; therefore, the
next query must be made when the VFD processing time has elapsed after the previous
query.
1 Subordinate address, function,
subfunction, and CRC check of the normal response are identical to those of
the query message.