Commissioning
EL5101, EL5101-0010, EL5101-0011
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Version: 4.2
Note
Maximum sampling frequency / minimum cycle time
A period shorter than 10 µs is not permissible for the EL5101-0011!
The maximum sample frequency for the EL5101-0011 is thus 100 kSps (samples per sec-
ond).
The cycle time may not be shorter than the minimum cycle time of 500 µs with an oversam-
pling factor of n = 50.
Regarding the calculation of SYNC0 from the SYNC1 pulse based on manual specification
of an oversampling factor, please note that for SYNC0 only integer values are calculated at
nanosecond intervals.
Sample: 187,500 µs are permissible, 333.3 are not.
Sample:
For SYNC1 = 1 ms oversampling factors such as 1,2,5 or 100 are permitted, but not 3! If implausible values
are use the terminal will reach the OP state but will not supply any process data.
This may result in a working counter error.
The 32-bit measured values accumulated in the buffer are sent as a packet to the higher-level control
system.
Time-related cooperation with other terminals
The reading of the measured values in the EL5101-0011 is triggered by an interrupt generated by the local
clock in the terminal. All local clocks in the supporting EtherCAT slaves are synchronized. This enables
EtherCAT slaves (here: terminals) to sample measured values simultaneously (simultaneous interrupt
generation), independent of the distance between them. This simultaneity is within the distributed clock
precision range of < 100 ns.
Sample:
Coordination of two EL5101-0011 terminals with each other:
The EtherCAT master, e.g. Beckhoff TwinCAT, configures both EL5101-0011 terminals such that their
SYNC1 pulses occur at the same time. Assumption: The EtherCAT bus cycle time is 500 µs. The SYNC1 is
thus triggered in all EL5101-0011 terminals every 500 µs. If both terminals operate with a corresponding
oversampling factor (e.g. 20), the SYNC0 pulse correlating to SYNC1 will occur simultaneously in all
EL5101-0011, in this sample every 25 µs. If different oversampling factors are used in the EL5101-0011
terminals employed, their SYNC0 pulses no longer occur simultaneously. The higher-level SYNC1 pulse is
retained.
Timestamp of the process data
The EL5101-0011 offers a "timestamp" for each process data block. This process data is already activated
as StartTimeNextLatch through the activation of 0x1A01 as a 64-bit value in Default on the Process data tab.
As the name suggests, the data block consisting of sample value+timestamp, which is transferred in each
cycle, is not related. The relationship is shown in Fig.
Temporal relationship between SYNC signals and
SyncManager
interrupt.
To explain in more detail:
• the sample is based on an oversampling factor n of 100
• the SYNC0 signal in the terminal fills the internal buffer with 100 position values
• SYNC1, which triggers the filled buffer to be made available as process data and at the same time
fetches the
StartTimeNextLatch
from the local distributed clock, runs synchronous with the cycle time.
• the data array is thereby assembled together with the next SYNC1 Time
• The next EtherCAT cycle fetches this data.
