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SRL 6-60 - Installation & Operating Manual -
819698-00
Function
Functional description of the SRL 6-60
The SRL 6-60 monitoring logic unit transmits the data telegram “Alert signal SRL 6-60” to the URS 60 / URS
61 safety control unit in 1s cycles.
The SRL 6-60 monitoring logic unit generates the time base for the purging intervals and monitors
compliance with these:
When the interval has elapsed, the standby time starts and the interval is reset to its initial value. The
purging process must be started within the standby time.
If the standby time is exceeded, the monitoring logic unit sends the commands “Open safety circuit” and
“Analyse limiter signal from LW level electrode 1 (2)” to the URS 60 / URS 61 safety control unit.
The start of the purging process is detected when valve
D
or
E
leaves the OPEN limit switch. The data
telegram: “Ignore limiter signal from LW level electrode 1 (2)” is sent to the URS 60 / URS 61 safety
control unit when the purging process starts, and the data telegram: “Analyse limiter signal from LW level
electrode 1 (2)” is sent at the end of the purging process.
What happens if the purge time is exceeded
If the purge time (5 min.) is exceeded, the monitoring logic unit sends the commands “Open safety
circuit” and “Analyse limiter signal from LW level electrode 1 (2)” to the safety control unit. The command
is only cancelled when the purging process has successfully completed.
When an external safety high level limiter is being monitored, the signals from the HW level electrode are
not analysed.
What happens during a purging process outside the standby time
The initiation of a purging process outside the standby time causes the interval to be reset. The interval is
factory set ( 24h or 72h ). The same applies to the standby time and purge time. These settings are shown
on the display of the monitoring logic unit.
Selecting the control unit and level electrode, see page 41
A menu in the monitoring logic unit enables you to select the safety control unit with which the monitoring
logic unit is to communicate, and which level electrode is to be monitored. The following points must be
adhered to:
Safety
control unit
ID
Level
electrode 1
ID
SRL 6-60
ID
Level
electrode 2
ID
SRL 6-60
URS 60
1
3 *
2
4 *
URS 61
5
7 *
6
8 *
* The ID of the SRL 6-60 monitoring logic unit is assigned automatically when the safety
control unit is selected, see page 40.
Fig. 5
