BECKHOFF ET1200 - Manual (Page 43)

PDI Description
Slave Controller – ET1200 Hardware Description III-33
6.2.8 SOF
SOF indicates the start of an Ethernet/EtherCAT frame. It is asserted shortly after RX_DV=1 or EBUS
SOF. Input data is sampled in the time interval between t
SOF_to_DATA_setup
and t
SOF_to_DATA_setup
after the
SOF signal is asserted.
6.2.9 OUTVALID
A pulse on the OUTVALID signal indicates an output event. If the output event is configured to be the
end of a frame, OUTVALID is issued shortly after RX_DV=0 or EBUS EOF, right after the CRC has
been checked and the internal registers have taken their new values. OUTVALID is issued
independent of actual output data values, i.e., it is issued even if the output data does not change.
6.2.10 Timing specifications
Table 37: Digital I/O timing characteristics ET1200
Parameter Min Max Comment
t
DATA_setup
8 ns Input data valid before LATCH_IN
t
DATA_hold
4 ns Input data valid after LATCH_IN
t
LATCH_IN
8 ns LATCH_IN high time
t
SOF
35 ns 45 ns SOF high time
t
SOF_to_DATA_setup
1,2 µs Input data valid after SOF, so that Inputs
can be read in the same frame
t
SOF_to_DATA_hold
1,6 µs Input data invalid after SOF
t
input_event_delay
440 ns Time between consecutive input events
t
OUTVALID
75 ns 85 ns OUTVALID high time
t
DATA_to_OUTVALID
65 ns Output data valid before OUTVALID
t
WD_TRIG
35 ns 45 ns WD_TRIG high time
t
DATA_to_WD_TRIG
35 ns Output data valid after WD_TRIG
t
OE_EXT_to_DATA_invalid
- - Not applicable for ET1200
t
output_event_delay
320 ns Time between consecutive output events
t
BIDIR_DATA_valid
65 ns Bidirectional mode: I/O valid before
OUTVALID
t
BIDIR_DATA_invalid
65 ns Bidirectional mode: I/O invalid after
OUTVALID
t
BIDIR_event_delay
440 ns Bidirectional mode: time between
consecutive input or output events