![Solcon HRVS-DN series Скачать руководство пользователя страница 147](http://html1.mh-extra.com/html/solcon/hrvs-dn-series/hrvs-dn-series_instruction-manual_1314370147.webp)
147 • HRVS-DN Communication (ModBus Protocol)
_______________________________________________________________________________________________
byte 3: Subfunction High
($00)
byte 4: Subfunction Low
($00)
byte 5: Data High
($37)
byte 6: Data Low
($A5)
byte 7: CRC_Low
($XX)
byte 8: CRC_High
($XX)
The normal (if no exception) response is the echo of the Query:
byte 1: Serial Link No.
($01)
byte 2: Function
($08)
byte 3: Subfunction High
($00)
byte 4: Subfunction Low
($00)
byte 5: Force Data High
($37)
byte 6: Force Data Low
($A5)
byte 7: CRC_Low
($XX)
byte 8: CRC_High
($XX)
16.13
Exception Responses
When the master sends a query frame to an HRVS-DN, one of the following four responses from the HRVS-
DN is possible:
1. When no communication error is detected in the query, and no mistake is found by the communication
program module in the HRVS-DN, a normal response is returned.
2. If the HRVS-DN does not receive the query frame (for example because of disconnected serial link cable)
then no response is returned by the HRVS-DN. After proper time the master will cause a timeout condition.
3. If the HRVS-DN receives the query, but faulty CRC bytes and / or Parity bits are detected, no response is
returned by the HRVS-DN. After the proper time the master will cause a timeout condition.
4. If no communication error is detected in the query, but the HRVS-DN communication program module
finds an error such as illegal Function, data address or data value, or if the HRVS-DN is busy, then an
Exception response is returned. The Exception response includes Exception Code to inform the master
about the type of the error.
Exception Code Response Frame:
The Exception response frame holds fix number of 5 bytes. The first one, the Slave Address field is the Serial
link number (transmitted in query and identical to HRVS-DN Serial Link No.). The second byte, the Function
field returns the echo of the transmitted query function, but with the Most Significant Bit set to 1 (adding $80 to
the transmitted function code). The third byte is the Exception Code informing about the type of error. The last
two bytes are the CRC bytes.
Exception Codes supported by the HRVS-DN:
Exception Code
Type
Comment
01
Illegal Function
Requested Function is not supported.
Functions 1..6, 8, 15 or 16 are supported.
02
Illegal Data Address
Data address is not allowable.
03
Illegal Data Value
Data Value is not in allowable range.
06
HRVS-DN Busy
HRVS-DN is busy now. The master retransmits the message
later.
Note: After using function 16 to store setting parameters, it is
forbidden to transmit again to the same MPR after less than
1Sec.
Example 10: