Characteristic Data Of S5-Compatible Communication (Send/Receive Interface) Over Fdl Connections - Siemens SIMATIC NET S7-300 - PROFIBUS Equipment Manual

Performance data

2.3 Characteristic data of S5-compatible communication (SEND/RECEIVE interface) over FDL connections

Other notes on FMS
Note: In FMS server operation, the CP occupies an unconfigured communication bus
connection in the S7 CPU.
Note that the S7 CPU 314 supports a maximum of 4 (maximum of 12 with newer CPU types)
unconfigured communication bus connections. If you operate a PG and an OP on the S7 CPU,
for example, two more unconfigured communication bus connections are free.
Note
Replace module without PG
CPU settings need to be modified to replace a module without a PG. For this purpose, select
the properties dialog of the CPU in HW Config; the following values must be checked and
increased if necessary in the "Monitoring time for..." input field in the "Startup" tab:
• "Transfer of parameters to modules"
Depending on the system (station expansion), you may also need to increase the value of the
following parameter:
• "Signaling readiness by modules"
2.3 Characteristic data of S5-compatible communication
(SEND/RECEIVE interface) over FDL connections
General characteristic data
The following characteristic data is important when operating FDL connections (specified,
free Layer 2 (SDA and SDN), broadcast, multicast):
Characteristic
Total number of FDL connections that can be
operated.
Size of the transferable data area for FDL
connections.
Reaction times of FDL connections
The calculation of the reaction times for FDL connections is largely dependent on the time
required to execute the function blocks (AG_SEND, AG_RECV) on the S7-300 / C7-300 CPU.
Component
Runtime in the CPU 314-1
(6ES7 314-1AE04-0AB0)
12
Explanation / values
16 max.
1-240 bytes max. per specified FDL connection
(for sending and receiving)
Free Layer 2, broadcast and multicast:
1 to 236 bytes of payload data can be transferred
per job. The job header occupies an additional 4
bytes.
Explanation / values
Per AG_SEND block call:
• 6.0 ms at 240 bytes
Equipment Manual, 05/2023, C79000-G8976-C160-04
Per AG_RECV block call:
• 7.5 ms at 240 bytes
CP 343-5