Siemens HydroRanger 200 HMI, Руководство по эксплуатации

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Communications
C.28 Parameter indexing
HydroRanger 200 HMI
334
Operating Instructions, 06/2018, A5E36281317-AC
C.28 Parameter indexing
Many parameters are indexed. There are two possible indexes: a primary index and a
secondary index. A secondary index is a sub-address of the primary index. Some indexed
parameters affect multiple I/O devices.
The following is an example of a primary index:
Relay Function (2.8.1.4.) (Page 195) is the Relay Control Function. This parameter
determines how a relay is controlled by the device (used as an alarm, for pump control, etc.).
Because there are up to six relays on the device, Relay Function (2.8.1.4.) (Page 195) is
indexed by six to allow each relay to be programmed independently.
A few parameters also have a secondary index. While a secondary index is important for
setting up the device, it is almost never needed through remote communications.
Indexing the parameter access area
Each parameter communicates its value to only one register. You must know the index(es)
for the parameter in order to interpret the information in the register correctly.
For example, to make use of the value returned in register R44,111 you must know which
relay it is referring to. See Relay function codes (2.8.1.4. Relay function only) (Page 343) for
details on Relay Function (2.8.1.4.) (Page 195) values.
To determine the index values, the primary and secondary index must be read or write. The
two possible methods of handling these index values are described in Global index method
(Page 335) and Parameter-specific index method (Page 336), below.
C.29 Reading parameters
To read parameter values, follow the steps listed in either the Global or the Parameter
specific index methods that follow. You must be able to program your HMI or SCADA system
before completing these methods.