
4-96
Chapter 4. Functions
z
Example: Internal cascade settings
In this example, the MV on the master side is converted to a 0 to 200 °C RSP,
control is done on the slave side, and the MV on the slave side is output from the
AO-C (current output) block of slot A2.
(1) Set so that the internal cascade can be used.
Use the SLP-C7 Smart Loader Package to set the loop type to "9: Internal
cascade."
(2) Set to convert the MV on the master side to the RSP on the slave side.
Use "Cascade bank" for the following settings.
Item (bank)
Display
Description
Setting value
Scaling method
(Cascade bank)
MENU > Cascade
Scaling method
0: Fixed
1: SP basis
2: PV basis
0
Scaling low limit
(Cascade bank)
MENU > Cascade
Scaling low limit
−32000 to +32000
0.0000
Scaling high limit
(Cascade bank)
MENU > Cascade
Scaling high limit
−32000 to +32000
200.00
Filter
(Cascade bank)
MENU > Cascade
Filter
0.0000: No filter
0.0001 to 120.00 s
0.0000
The RSP conversion calculation formula may vary depending on the scaling
method.
•
When set to "0: Fixed," RSPs = (MVm ÷ 100) × (SH − SL) + SL
•
When set to "1: SP basis," RSPs = (MVm ÷ 100) × (SH − SL) + SL + SPm
•
When set to "2: PV basis," RSPs = (MVm ÷ 100) × (SH − SL) + SL + PVm
The variables used in the calculation formulas have the following meanings.
SL: Scaling low limit
SH: Scaling high limit
MVm: MV on master side
SPm: SP on master side
PVm: PV on master side
RSPs: RSP on slave side
The filter reduces the effect that the vibrations of the MV on the master side have
on the RSP on the slave side.
(3) Output the MV on the slave side from the AO-C (current output) block of slot
A2.
Use "Analog output bank" for the following settings.
In this example, the 0 to 100 % range of the MV on the slave side (loop 2) is
output in the range from 4 to 20 mA.