Azbil SDC35 - Page 78

5-18
Chapter 5. DETAILED DESCRIPTION OF EACH FUNCTION

ON/OFF control
The ON/OFF control related items can be set.
Item (Bank) Display Contents Initial value User level
ON/OFF control differential
(Parameter bank)
0 to 9999U 5U Basic,
Standard,
High function
ON/OFF control operating
point offset (Parameter
bank)
-1999 to +9999U 0U High function
• [ON/OFF control differential:
dI

FF
] and [ON/OFF control operating point
offset:
OFFS
] can be displayed and set when the control method is the ON/OFF
control (
CtrL
= 0).
• The following Figure shows the operation of the ON/OFF control:
SP + OFFS
Heat control (Reverse action) Cool control (Direct action)
PV
ON
dI FF
SP + OFFS
PV
ON
dI FF

shows that the ON/OFF is changed at this value.

shows that the ON/OFF is changed at a point that "1U" is added to this
value.
• The following describes examples showing how to use the ON/OFF control
operating point offset:
To turn OFF the output at 205°C or more and turn ON the output at less than
190°C with the heat control and SP = 200°C, the differential is set to 15°C and
the offset is set to 5°C.
To turn OFF the output at 5°C or less and turn ON the output at more than 10°C
with the cool control and SP = 10°C, the differential is set to 5°C and the offset is
set to -5°C.

Output variation limit
Variation in the manipulated variable (MV) can be limited.
Item (Bank) Display Contents Initial value User level
Output variation limit
(Parameter bank)
0.0: No limit
0.1 to 999.9%
0.0 High function
• The upper limit (%) for the absolute value of MV variation can be set in 1s
intervals. However, because the sampling cycle is 0.1s, the actual MV variation
is limited to 1/10 of the value set. For example, when 5.0(%/s) is set, the variation
per 0.1s is limited to ±0.5%. In addition, when 0.1(%/s) is set, the variation per
0.1s is limited to ±0.01%.
• When 0.0 is set, there is no limit on MV variation.
• When the model is a motor drive relay output type with a motor long life mode
(
C59
= 1), display and setting are not possible because the MV variation limit
function operates automatically.