Siemens SIMATIC PCS 7 FOUNDATION Fieldbus Commissioning Manual page 44

Engineering
5.3 Parameter assignment
Timer T2 operates on the FF devices.
Bus parameters Setting range (default
setting)
T1 -
Inter Sequence (480 000
Timer
corresponds to approxi‐
mately 15 s)
T2 Rule: T2 >= T3 + 3*T1
(host)
Set Addr Se‐
quence Timer (2880000
corresponds to approxi‐
mately 90 s)
T3 -
Set Addr Wait (1 440 000
Timer
corresponds to approxi‐
mately 45 s)
"Node Polling" area
Bus parameters Setting range (default
setting)
First Unpolled 20 < FUN < 232
Node
Number of Con‐ NUN = 232 - FUN
secutive Unpol‐
led Node
"Other bus parameters" area
Select the option for setting the parameters:
● "Automatic calculation"
The bus parameters are automatically set on the basis of the current configuration.
● "Manual entry" option
You can change the following parameters for each specific system.
44
Meaning and limiting values
The parameter T1 specifies the number of clock cycles that an interface module
(or an LAS) waits for a response from an FF device.
If the set number of clock cycles is exceeded, the service for this FF device will
terminate with an error message.
The parameter T2 specifies the number of clock cycles that is available to an
FF device for actions and data transfer. Any unperformed actions and data
transmissions are cancelled.
FF devices newly connected to the FF segment can only be detected if the value
T2 is sufficiently dimensioned.
The parameter T3 corresponds to the number of clock cycles that are available
as waiting time.
On expiration of this waiting time the interface module (or LAS) checks the FF
devices that are recognized as new on the FF.
Meaning and limiting values
FirstUnpolledNodeId (FUN)
Default setting in SIMATIC PCS 7: FUN = 36
This parameter specifies the first device address that is not processed (not pol‐
led) by the LAS.
NumConsecUnpolledNodeId (NUN)
Default setting: NUN = 232 - 36 = 196
Range of consecutive device addresses not in the polled range.
In SIMATIC PCS 7 (Unpolled Bereich):
Default setting of 36 - 231
FOUNDATION Fieldbus
Commissioning Manual, 02/2015, A5E32711026-AC