Timestamp function

The timestamp is made possible by the distributed clocks technology in the EtherCAT system. This local clock can be used to synchronize the data acquisition.

The ED5112 provides a timestamp for the following input signals:

Last counter change in the PLC cycle
Zero pulse C input: when storing the counter value on the positive edge of the zero pulse C
Latch input: when storing the counter value on the selected edge of the latch input
Gate input: when storing the counter value on the selected edge of the “Gate” input

	Note on using the timestamp function In order to be able to use the timestamp function, the terminal must be operated in “DC‑Synchron” or “DC‑Synchron (input based)” mode.

The terminal provides the timestamp in a range of 64 bits, optionally with only 32 bits. The timestamps are contained in the following “Predefined PDO Assignment”:

Predefined PDO Assignment
1.Ch Standard, 1xABC, extended DC mode, 64 Bit time stamp
1.Ch Standard, 1xABC, extended DC mode, 32 Bit time stamp

They can be selected or deselected as optional PDOs.

PDO assignment	Name	Description
0x1A0D	ENC Timestamp Channel 1	Contains timestamps in the 64 bit range for channel 1
0x1A0E	ENC Timestamp Compact Channel 1	Contains timestamps in the 32 bit range for channel 1

Timestamp for the last counter change in the PLC cycle

The process data “Timestamp” (0x60n0:16) indicates the timestamp of the last registered counting pulse in the PLC cycle. This means, depending on the counter evaluation mode (index 0x80n0:06 “Evaluation mode”) the timestamp is output based on:

0x80n0:06 “Evaluation mode”		0x60n0:16 “Timestamp”
0	4-fold (default)	last positive or negative edge on track A or B
1	1-fold	last positive edge on track A
2	2-fold	last positive or negative edge on track A

Timestamp on input zero pulse C

The process data “Timestamp C” (0x60p0:1F) outputs the timestamp of the last registered positive edge of the zero pulse C when the counter value is saved.

Parameterization of the zero pulse C input		0x60p0:1F: “Timestamp C” returns the timestamp:
0x70p0:01	Enable latch C	the positive edge of the zero pulse C at which the counter value was stored in the input process data “Latch value” (0x60p0:12)
Depending on the number of channels, the following applies: p = 0 for Ch1, p = 1 for Ch2

Timestamp for the “Latch extern” input

The input process data “Timestamp latch” (0x60p0:20) specifies the timestamp for the selected edge of the “Latch extern” input. This means that, depending on the parameterization of the “Latch extern” input, the timestamp is valid for:

Parameterization of the Latch input		0x60p0:20 “Timestamp latch” returns the timestamp based on:
0x70p0:02	Enable latch extern on positive edge	the last positive edge at the “Latch extern” input, at which point the counter value was stored in the input process data “Latch value” (0x60p0:12)
0x70p0:04	Enable latch extern on negative edge	the last negative edge at the “Latch extern” input at which the counter value was stored in the process data “Latch value” (0x60p0:12)
Depending on the number of channels, the following applies: p = 0 for Ch1, p = 1 for Ch2

Timestamp on “Gate” input

The input process data “Timestamp latch 2” (0x60p0:21) specifies the timestamp on the selected edge of the “Gate” input. The “Gate” input can also be used as “Latch extern 2” input. Depending on the parameterization of the “Latch extern 2” input the timestamp is valid for:

Parameterization of the “Latch 2” input		0x60p0:21 “Timestamp latch 2” returns the timestamp based on:
0x70p0:0C	Enable latch extern 2 on positive edge	the last positive edge at the “Gate” input, at which point the counter value was stored in the process data “Latch value 2” (0x60p0:22)
0x70p0:0D	Enable latch extern 2 on negative edge	the last negative edge at the “Gate” input, where the counter value was stored in the input process data “Latch value 2” (0x60p0:22)
Depending on the number of channels, the following applies: p = 0 for Ch1, p = 1 for Ch2