ABB DCS 500B, Description

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Functional Software description
DCS 500 Software Description 27
The inputs [SEL1] (1911) , [SEL2] (1913) , [SEL3] and (1915) con-
trol which of the reference signals ([IN1]...[IN3]) is connected to the
SUM block inside the REF SEL function block. Only one of the sig-
nals
IN1 , IN2 or IN3 can be connected to the SUM block at a time.
[ADD] (1916) is always connected to the SUM-block.
Changing of the
speed direction
of rotation Input [REV] (1917) controls the output selection of the SUM-block.
If this input is set to logical state 1, the speed reference at the OUT
(10202) is negated. This can be used to change the rotation of di-
rection on a 4Q-drive.
RAMP GENERATOR
function block The main function of the RAMP GENERATOR function block is to
accelerate and decelerate the motor’s speed with selected time
constants to the value of
[IN] (1701) .
SMOOTH
1 & 2
SMOOTH ACTION
OUTPUT OF THE RAMP
IN (1701)
0
20000
DECEL
1 & 2
ACCEL
1&2
SMOOTH
1 & 2
Figure 14 Function of the Ramp Generation function block
Local / Remote
Speed Reference There are two switches in front of the ramp block. The first switch
is the
LOCAL/REMOTE selector. When LOCAL control is selected
from, for example, the CDP312 control panel, the speed reference
comes from the panel link. In
REMOTE control the reference
comes from the input pin [IN] (1701) .
The second switch sets the reference to zero at the input of the
ramp by means of
[RES IN] (1702) input pin.
Holding of the
reference If the [HOLD] (1703) input is in logical state 1, the output of the
ramp is holding the old value.
Ramp Function in
Emergency Stop If emergency stop function is activated by drive logic EME STOP
MODE (907) = 1, then the deceleration time is read from the pa-
rameter EMESTOP RAMP (1714) .