Siemens SINAMICS G120 - Page 156

Configuring the fieldbus
7.6 Communication via RS485
Inverter with CU230P-2 Control Units
156 Operating Instructions, 11/2013, FW V4.6.6, A5E02430659B AG
Parameter contents
Parameter contents can be parameter values or connector parameters. You require two
words for connector parameters. For interconnecting connector parameters please see
Section Interconnecting signals in the converter (Page 425).
Enter the parameter value in the parameter channel right-justified as follows:
•
8-bit values:
Low word, bits 0
… 7,
bits 8
… 15 are zero.
•
16-bit values:
Low word, bits 0 … 15,
•
32-bit values:
Low word and high word
Enter a connector parameter right-justified as follows:
•
Number of the connector parameter:
High word
•
Drive object of the connector parameter:
Low word, bits 10 … 15
•
The index or bit field number of the connector parameter:
Low word, bits 0 … 9
Telegram examples, length of the parameter channel = 4
Read request: Read out serial number of the Power Module (p7841[2])
To obtain the value of the indexed parameter p7841, you must fill the telegram of the
parameter channel with the following data:
●
PKE, bit 12 … 15 (AK): = 6
(request parameter value (field))
●
PKE, bit 0 … 10 (PNU): = 1841
(Parameter number without offset)
Parameter number = PNU + offset (page index)
(7841 = 1841 + 6000)
●
IND, bit 8 … 15 (page index): = 90 hex
(offset 6000 ≙ 90 hex)
●
IND, bit 0 … 7 (subindex): = 2
(Index of the parameter)
● Because you want to read the parameter value, words 3 and 4 in the parameter channel
for requesting the parameter value are irrelevant. They should be assigned a value of 0,
for example.
Figure 7-11 Telegram for a read request from p7841[2]