Introduction
The PROFIBUS subnet will only function problem-free if the parameters for the bus profile are matched to one another. You should therefore only change the default values if you are familiar with how to configure the bus profile for PROFIBUS.
It may be possible for the bus parameters to be adjusted depending on the bus profile. The offline values of the bus parameters are always shown even if you are online and linked to the target system.
The displayed parameters are valid for the entire PROFIBUS subnet.
Meaning of the individual parameters
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Tslot: Wait-to-receive time (slot time)
The wait-to-receive time (slot time) defines the maximum time the sender will wait to receive a response from the addressed partner.
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Max. Tsdr: maximum protocol processing time (max. station delay responder)
The maximum protocol processing time defines the time after which the responding device must have processed the protocol.
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Min. Tsdr: minimum protocol processing time (min. station delay responder)
The minimum protocol processing time specifies the minimum time required by the responding device to process the protocol.
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Tset: Trigger time (setup time)
The trigger time is the time that may lapse between the reception of a data frame frame and the reaction to it.
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Tqui: Quiet time for modulator
The quiet time for modulator specifies the time required to change from sending to receiving.
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GAP factor: GAP update factor (GAP factor)
The GAP update factor specifies the number of token rotations before a new device is included in the token ring.
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Retry limit: maximum number repeated calls (retry limit)
This parameter defines the maximum number of attempts (message frame repeats) made to reach a node.
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Trdy: Ready time
The ready time is the time for an acknowledgment or response.
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Tid1: Idle time 1
Idle time 1 specifies the delay time after receiving a response.
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Tid2: Idle time 2
Idle time 2 specifies the delay time after sending a call without a response.
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Ttr: Target rotation time
The target rotation time is the maximum time made available for a token rotation. During this time, all active devices (masters) receive the token once. The difference between the desired token round-trip time and the actual token round-trip time decides how much time is left for masters to send data message frames to the slaves.
As the minimum target rotation time (Ttr), select a value = 5000 times the HSA (Highest Station Address).
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Watchdog: Watchdog
The watchdog time specifies the time after which a device must be addressed.
As the minimum watchdog time, select a value = 6250 times the HSA.
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Note If you want to create a user-defined bus profile, note that the minimum target rotation time (Ttr) should be 5000 times the HSA (highest PROFIBUS address). The minimum watchdog time should also be 6250 times the HSA. |