MODBUS LITE V5.01 parameter specification

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: [phone] ·Fax: [phone] ·www.ebmpapst.com ·[e-mail]
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
Function:
When the system is being set up, the fans have to be arranged in ascending order by serial number. This is
the prerequisite for ensuring that the automatically assigned MODBUS addresses can easily be correlated
with the fans in the system.
At the beginning, all fans are set to MODBUS address 0x01.
For this purpose, 2 broadcast commands are required:
 Set the holding register fan address (D100) to 0x01: 00 06 D1 00 00 01 CS CS
(CS = CRC checksum)
 Set the holding register reset (D000) to 0x02 Adopt parameters: 00 06 D0 00 00 02 CS CS
All of the serial numbers in the system are determined in a loop:
The screen for serial number addressing is set initially to broadcast addressing
(00 00 00 00 00 00). The last byte is set to the start value of 0x30 (0).
The SerNr screen is thus 00 00 00 00 00 30.
This screen searches for fans that have the value 0x30 (0) in the last position of the serial number.
Any command for reading a holding register or input register can be used, e.g. Read holding register fan
address: 01 43 00 00 00 00 00 30 D1 00 00 01 CS CS
There are several possibilities for the response:
 There is a unique response.
The connected fan responds with its serial number in the address field (SerNrVent).
This serial number is stored in a list.
Then, the fan is blocked from further queries by setting the MODBUS address to 0xF7 (247).
The same serial number then has to be queried again, as the possibility cannot be eliminated that another
fan was also addressed, but did not respond because it already detected the beginning of the other fan's
response due to run time differences.
 There is an invalid response due to overlapping responses from multiple fans.
Then the serial number screen needs to be limited further by also setting the next-to-last byte to the start
value of 0x30 (0). The next query now gets a response only from fans that have the value 0x30 (0) in the
last two digits of the serial number.
 There is no response.
In this case, all serial numbers that have the value 0x30 in the last position can be eliminated. The last
byte of the screen is increased to the value 0x31 (1). On the next query, all fans that have the value
0x31 (1) in the last position of their serial numbers will respond.
The loop is now continued until all serial numbers have been queried.
 If a valid response is given, the serial number of the fan is stored in the list.
 In case of an invalid response, the serial number range is restricted further by masking an additional byte,
beginning with the start value. For the last 4 bytes, the start value is 0x30 (0). The first two bytes have the
start value 0x01, as the year (2001) and calendar week (week 1) are encoded here.
 If there is no response, the respective position is increased by 1 until the end value is reached.
For the last 4 bytes, the end value is 0x5A (Z). For the first byte (year), the end value is 0x63 (2099);
for the second byte (calendar week), the end value is 0x35 (week 53).
When the end value is reached, the respective position is again addressed via broadcast (0x00) and the
next position is increased by 1. When addressing for the last byte reaches the end value 0x5A (Z), all
serial numbers have been checked and serial number querying can be concluded.