Performance data and behavior in operation
5.4 Characteristic data of open communications services (SEND/RECEIVE interface) over FDL connections
CP 342-5 / CP 342-5 FO
Manual, 10/2011, C79000-G8976-C146-09
27
Note
Time values are guidelines
The times shown for DP slave mode should only be considered as guideline values. The
values apply only when no other services (for example PG functions) are processed on the
CP.
5.4
Characteristic data of open communications services
(SEND/RECEIVE interface) over FDL connections
General characteristic data
The characteristic data is important when operating FDL connections (specified, free layer 2
(SDA and SDN), broadcast, multicast):
Characteristic
Explanation / values
Total number of FDL connections that can be
operated.
16 max.
Size of the transferable data area on FDL
connections.
1-240 bytes maximum per specified FDL
connection (for sending and receiving):
Free Layer 2, broadcast and multicast:
Up to 236 bytes of user data can be transferred
per job. The job header occupies an additional 4
bytes.
Execution times of the program blocks AG_SEND / AG_RECV
The following table will help you to calculate the CPU cycle times (OB1) for FDL
connections. The table contains the execution time of the FCs (FC AG_SEND, FC
AG_RECV) required for DP processing on the S7-300 / C7-300 CPU.
Component
Explanation / values
Execution time on the CPU
314C-2DP (6ES7 314-6CF00-
0AB0)
Per AG_SEND block call:
<5.1 ms at <=240 bytes
Per AG_RECV block call:
<5.7 ms at <=240 bytes
Execution time on the CPU 317-
2PN/DP (6ES7 317-2EJ10-
0AB0)
Per AG_SEND block call:
<2.4 ms at <=240 bytes
Per AG_RECV block call:
<2.8 ms at <=240 bytes
