Modbus Parameter Specifications

MODBUS ACE V1.00
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DocNo.: 634505DocNo: 446144DocNo.:358982DocNo.:322523DocNo.:309753DocNo.:303997DocNo.:276241DocNo.:256078DocNo.:196392 ·Template: 2 dated 10/6/2003 ·File: ext001931381.docx ·Last printed 9/30/2019 10:29:00
AM ·Page 49 of 78
Form 1003
Note:
If parity configuration 8N1 is selected, the device no longer corresponds to the MODBUS specification
"MODBUS over Serial Line Specification & Implementation Guide V1.0", as this specifies a mandatory
11-bit frame.
It must be ensured that the parity configuration selected for the fan is the same as that in the master
(e.g. EC-Control). Communication with the fan is otherwise not possible.
If the value of the customer setting (holding register D24A) or the factory setting (holding register D2CA)
differs from the value selected here, it must be ensured that the parity configuration has been accordingly
altered following completion of data transfer from the customer setting or factory setting. Communication is
then no longer possible with the previous setting.
2.34.3 Procedure for changing interface setting
Communication is not possible if the parameters "Transmission speed" and "Parity configuration" do not
correspond to the setting for the interface in the master (e.g. EC-Control).
If the setting differs, the interface setting cannot be polled from the fan, i.e. it is essential to know the interface
setting of the fan.
To avoid complications resulting from different interface settings, it is advisable to leave the interface settings
on the default values:
Transmission rate : 19200 bits/sec (0x04)
Parity configuration : 8E1 (0x00)
If a change is necessary, care must be taken to ensure that the master and fan always have the same setting
so as to ensure faultless communication.
The new interface setting of the fan is only adopted following a corresponding command to the parameter
"Reset" (Transfer parameter or Reset) or after switching off the device ("Power off"). Until then the fan
operates with the existing setting.
Recommended procedure for changing the interface setting, based on the example of a change from 19200
bits/sec, 8E1 to 38400 bits/sec, 8N2:
 To start with, the interface setting at the master must be 19200 bits/sec, 8E1.
 Write password: XX 10 D0 02 00 03 06 PP PP PP PP PP PP CS CS
(The minimum authorization required for changing the interface setting is "Customer")
 Write transmission speed with value 38400 bits/sec: XX 06 D1 49 00 05 CS CS
 Write parity configuration with value 8N2: XX 06 D1 4A 00 02 CS CS
 Trigger Transfer parameter: XX 06 D0 00 00 02 CS CS
 Following acknowledgment of the command by the fan, it will operate with the new setting.
 Change interface setting in master: 38400 bits/sec, 8N2
XX ................... Fan address
PP ................... Password
CS ................... CRC checksum