Chapter 7 Usage of Various Functions
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(g)
Proportional gain
The MK80S can handle only integer, not the floating point type. Therefore, to enhance the accuracy of PID
operation, the PID8 instruction is designed to input the P_GAIN data as the 100 times scaled up. For example, if the
designated P_GAIN is 98, actual input data of P_GAIN should be 9800. If the designated P_GAIN is 10.99, input
1099 to the P_GAIN.
(h)
Mode command set
In MK80S, only the following 4 operation modes are available. Other operation modes, such as PD or I, are not
permitted.
No.
EN_P
EN_I
EN_D
Operation
1
1 (enable)
0 (disable)
0 (disable)
P operation
2
1 (enable)
1 (enable)
0 (disable)
PI operation
3
1 (enable)
1 (enable)
1 (enable)
PID operation
4
0 (disable)
0 (disable)
0 (disable)
On/Off operation
(i)
Bias value
The Bias data is used for the compensation of offset in the proportional control.
(j) SV(Target)
SV (setting value : the designated value) and PV (process value : present value) of MK80S PID operation have the
range 0 ~ 4000. The range is set with the consideration of the resolution of A/D and D/A module of MK80S series
(12bits) and offset value.
The following table shows error codes and descriptions of PID8 instruction.
Error code
(STAT output)
Description
Countermeasure
0 Normal
operation
1
SV is out of range
Change the SV within 0 ~ 4000
2
MVMAN is out of range
Change the MVMAN within 0 ~ 4000
3
P_GAIN is out of range
Change the P_GAIN within 0 ~ 10000
4
I_TIME is out of range
Change the I_TIME within 0 ~ 20000
5
D_TIME is out of range
Change the D_TIME within 0 ~ 20000
6
S_TIME is out of range
Change the S_TIME within 0 ~ 100
7
REF is out of range
Change the REF within 0 ~ 10
8
TT is out of range
Change the TT within 0 ~ 1000
9
N is out of range
Change the N within 0 ~ 1000
10
EN_I and/or EN_D is set as 1
when EN_P is 0
Only P, PI, and PID controls are available. Please
change the setting of EN_P, EN_I, and EN_D.
1. Please be careful to input 100 times scaled up values for P_GAIN and TT.
2. I_TIME, D_TIME, S_TIME, and REF are 10 times scaled up, not 100 times.
Remark
