VIBRATION TRANSMITTER-VT7S12E
Ref No: mVTD/om/201
Issue No: 02
User’s Manual
- 17 -
8. RELAY OUTPUTS
Following function can be set for Relay outputs.
Relay Logic (Direction):
Relay Logic means Relay contact can be changed from Open to Close OR Close to Open. If relay logic is selected Normal,
when Fault occur Relay contact will change from Close to Open. If relay logic is selected Fail Safe, when Fault occur Relay
contact will change from Open to Close.
Relay Function:
Relay function can be selected as ALARM or TRIP.
If relay is selected as ALARM, when abnormal condition occur Relay will ON, once normal condition after abnormal condition
occur Relay will OFF.
If relay is selected as TRIP, when abnormal condition occur Relay will ON, once normal condition after abnormal condition
occur Relay will ON. Relay will be off through Acknowledge.
Relay Delay:
A time delay can be provided for the actual output.
Relay Open Sensor
: Open sensor upscale or down scale can be selected for each relay output.
Relay Mapping:
Refer Menu layout LEVEL - 2
Relay Types:
Various relay operations are shown in the reference figure. (High, Low, Very High- High, Low-Very Low, High-
Low). For relay types selection Refer Menu layout LEVEL
– 2.
Control Output (ON/OFF Control ) :-
ON/OFF Controller is the simplest form of temperature control device. The output from the device is either on or off, with no
middle state. An on-off controller will switch the output only when the temperature crosses the set point. For heating control,
the output is on when the temperature is below the set point, and off above set point. Since the temperature crosses the set
point to change the output stage, the process temperature will be cycling continually, going from below set point to above, and
back below. In cases where this cycling occurs rapidly, and to prevent contactors and valves from getting damaged, an on-off
differential, or “hysteresis,” is added to the controller operations. This hysteresis assures, if temperature exceed set point by a
certain amount before then only output will turn off or on again. On-Off hysteresis preven
ts the output from “chattering” or
making fast, continual switches if the cycling above and below the set point occurs very rapidly.
Relay type High (H-ON):
For High type of set value, once process value reaches up to set point + Hysteresis value,
relay will be ON after few seconds (as per relay delay) and it will be ON until process value goes down to Set point.
Relay type Low (L-ON):
For Low type of set value, once process value reaches down to set point - Hysteresis value relay will be ON after nearly
few seconds (as per relay delay) and it will be ON until process value goes up toward Set point.
NOTE:-
VT7S12E has both Control Logic (ON-OFF) & Alarm Logic. If Control Logic (ON-OFF) is required,
rloP
in
lvl2
must
be selected as
Co
.
Whenever Control Output (ON-OFF) logic is selected, all relays are mapped as shown in chapter no.6. As well as, relay
latch is off and relay group is assigned as relay per group 1. In this logic, user cannot change relay mapping, relay
latch and relay group and user cannot acknowledge relays.
