MODBUS LITE V5.01 parameter specification

Table Of Contents
MODBUS parameters "ebm-papst series 84 / 112 / 150 / 200"
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ebm-papst Mulfingen GmbH & Co. KG
Bachmühle 2 ·74673 Mulfingen, Germany ·Phone: +49 (0) 7938/81-0 ·Fax: +49 (0) 7938/81-110 ·www.ebmpapst.com ·info1@de.ebmpapst.com
DocNo.: 634505DocNo.: 446144DocNo.:358982DocNo.:322523DocNo.:309753DocNo.:303997DocNo.:276241DocNo.:256078DocNo.:196392 ·Template: 2 dated 6 October 2003 ·File: ext001157859.doc ·Last printed 10/03/2015 15:13:00
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Form 1003
Afterwards, all serial numbers found in the master are sorted in ascending order.
Each fan is assigned a MODBUS address via the serial number.
For this purpose, 2 commands are required per fan:
Set the holding register fan address (D100): F7 46 SNr SNr SNr SNr SNr SNr D1 00 00 Adr CS CS
Set the holding register reset (D000) to 0x02 Adopt parameters:
F7 46 SNr SNr SNr SNr SNr SNr D0 00 00 02 CS CS
SNr = determined serial number of the fan; Adr = assigned MODBUS address
Extension of the address space
Up to 247 fans can be addressed with standard MODBUS commands.
Commands with addressing via serial number offer the possibility of addressing an unlimited number of ebm-
papst fans using the MODBUS interface. In this case, the address of the fan is not just made up on one byte,
but rather of 7 bytes (MODBUS address + 6 byte serial number). This address is defined in the factory and
cannot be changed.
For the purpose of addressing, the serial number must be known in the master device (e.g. PC) as a scan of
all serial numbers is not possible due to the large numbers involved. To identify the serial number, see above
(Initialising a system).
Only commands with addressing via the serial number can be used with an extended address space. When
standard commands are used, conflicts are inevitable as several fans will have the same MODBUS address.
Identifying an unknown MODBUS address
Only one fan may be connected to the bus
Command 0x43 Read Holding Register Addressed By Serial No. or 0x44 Read Input Register Addressed
By Serial No. in broadcast addressing:
MODBUS address and serial number identification are specified using 0x00
The connected fan responds with its MODBUS address and serial number
1.3.7 Other commands
All other commands are not supported.
A command is always responded to with exception code 0x01.