RKC INSTRUMENT COM-JG, Инструкция по эксплуатации

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6. PROFIBUS COMMUNICATION
IMR01Y35-E3
22
6.2 PROFIBUS Communication Data
6.2.1 Data types and data length of communication data
Data access types
•
Static data read/write
•
Dynamic data read/write
•
Error state register
•
Write permission flag register
•
Write control flag register
Communication data length
A maximum of 170 bytes can be read or written.
Static data request
The maximum number of communication items which can be specified:
40 items (Read items
＋
Write items)
The communication items which can be specified:
Data of the 7. COMMUNICATION DATA MAP (P. 28)
Dynamic data request
The communication items which can be requested:
Data of the 7. COMMUNICATION DATA MAP (P. 28)
The number of communication items becomes as follows depending on the number of
connection channels.
[Read data] Number of static read data
×
Number of connection channel
a
×
2
+
Number of dynamic data
×
6
+
12
b
≤
170
[Write data] Number of static write data
×
Number of connection channel
a ×
2
+
Number of dynamic data
×
6
+
11
c ≤
170
a
Total number of continuous accesses
b
(Error state register: 1 byte) ＋ (Write permission flag register: 1 byte) ＋ (Write control flag register: 10 bytes)
=
12
c
(Write permission flag register: 1 byte) ＋ (Write control flag register: 10 bytes)
=
11
Number of connection channels Number of static data *
1 channel Maximum of 40 items for both read and write.
16 channels Maximum of 5 items for both read and write.
31 channels Maximum of 2 items for both read and write.
*
Calculated with the number of dynamic data equal to 0. The 10 bytes of the write control flag register
for read data and the 10 bytes of the write control flag register for write data can be omitted.
6.2.2 Static data request
•
Static data is that which is always read/written from/to the PROFIBUS master such as the PLC. The
data item is selected by the configuration tool such as the PLC.
•
As the Modbus register address is directly specified, data items of all the controllers connected to the
COM-JG can be selected.
•
When static data is requested, 1-word (2-byte) data is used for both read and write.
As the static data register address is set when system configured, it is not required to create a
sequence program for static data assignment.