Endress+Hauser Silometer FMC 672 Z, Инструкция по установке и эксплуатации

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7 Limit Switches
This Chapter describes the setting of the relay limit switches. It is divided into two
Sections:
•
Control parameters
•
Relay operating modes
Silometer FMC 672 Z/677 Z transmitters have two independent relays, which switch
according to the size of the measured value at V0H0/V4H0 on the channel to which they
are assigned.
•
Each limit switch can be operated in minimum or maximum fail-safe mode,
i.e. when the level drops below or exceeds the switch point the relay is
de-energized.
•
The hysteresis of each limit switch is freely selectable. This determines the
point at which the limit switch re-energizes the relay.
•
Relay 1 is normally assigned to output 1 and relay 2 to output 2, however, the
assignment can be changed.
The switch points are entered in the units selected during calibration and linearization,
i.e:
•
No linearization: level units entered
•
No linearization, calibration in volume units: volume units entered
•
Linearization: volume units entered
The relays are controlled by the matrix fields V1H0 to V1H4 for relay 1 and V5H0 to V5H4
for relay 2. Table 7.1 summarizes their function.
Relay 1 Relay 2 Significance Default
V1H0 V5H0 Relay switch point 90
V1H1 V5H1 Fail-safe mode
0 = Minimum:
relay de-energises when level < switch point
1 = Maximum:
relay de-energises when level > switch point
On fault condition
relay reacts according to V1H3/V5H3 setting
see Section 5.2
1
V1H2 V5H2 Relay hysteresis 2.0
V1H3 V5H3 Relay at fault
0 = de-energises
1 = follows analogue output 1/2 according to
settings at V0H7 and V4H7
0
V1H4 V5H4 Relay assignment
1 = analogue output 1
2 = analogue output 2
1/2
Table 7.1:
Relay control parameters
Silometer FMC 672 Z/677 Z Chapter 7: Limit Switches
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