Hach-Lange RTC112 SD-Module - Manual (Page 25)

25
Parameterization and operation
INPUTS
CHANNEL 1
MIN FEED FLOW
Minimum flow rate [m³/h] from the influent in accordance with
the 0/4 mA measurement signal.
m³/h
MAX FEED FLOW
Maximum flow rate [m³/h] from the influent in accordance with
the 20 mA measurement signal.
m³/h
0/4...20mA
Transfer range of 0/4 to 20 mA current loop (as set in connected
flow measuring instrument).
MIN POLYMER FLOW
Minimum polymer dosing in [L/h] in accordance with the 0/4 mA
measurement signal.
L/h
MAX POLYMER FLOW
Maximum polymer dosing in [L/h] in accordance with the 20 mA
measurement signal.
L/h
0/4...20mA
Transfer range of 0/4 to 20 mA current loop (as set on
connected flow measuring instrument).
CHANNEL 2 As per channel one
OUTPUTS
CHANNEL 1
MIN FEED FLOW Minimum feed flow rate [m³/h] in accordance with 0/4 mA. m³/h
MAX FEED FLOW Maximum feed flow rate [m³/h] in accordance with 20 mA. m³/h
0/4...20mA
Transfer range of 0/4 to 20 mA current loop (as set on
connected flow measuring instrument).
MIN POLYMER FLOW
Minimum polymer pump delivery rate in accordance with
0/4 mA.
L/h
MAX POLYMER FLOW
Maximum polymer pump delivery rate in accordance with
20 mA.
L/h
0/4...20mA
Transfer range of 0/4 to 20 mA current loop (as set on
connected flow measuring instrument).
CONTROL CYCLE
Pulse/pause mode for the polymer pump open-loop control for
dosing rates beneath the minimum polymer flow rate (MIN
POLYMER FLOW). The on/off duration in pulse/pause mode
can be affected by the duration of the CONTROL CYCLE. For
example, with a CONTROL CYCLE of 100 seconds and a
dosing control value of 60 %, the polymer pump is regularly
switched on for 60 seconds and switched off for 40 seconds.
Short cycle times increase the switching frequency but enable
more precise adaptation to individual requirements. CONTROL
CYCLE should be divisible by MIN RUNTIME and produce a
whole number.
s
MIN RUNTIME
The minimum ON time in pulse/pause dosing mode. The pump
is not activated for periods shorter than this. The MIN RUNTIME
must be shorter than the duration of the CONTROL CYCLE.
s
CHANNEL 2 As per channel one
4.4.1 RTC112 SD-Module open and closed-loop controller (Continued)
RTC MODULES / PROGNOSYS
RTC MODULES
RTC