4.6.4.2   Discrete Calculation Tag Examples

4.6.4.2.1 FLIP_FLOP

This Calculation Tag example calculates creates flip-flopping tag the oscillates from 0 to 1 to 0. 

Tag Type Calculation  (discrete)

Tag Name CalcLogicDigital    

Description Test if nonzero - flip from 0 to 1 to 0    

Evaluate frequency 3  Second  

Initial Value 0    

State 0 OFF    

State 1 ON    

State 2 NotUsed    

State 3 NotUsed    

State 4 NotUsed    

State 5 NotUsed    

State 6 NotUsed    

State 7 NotUsed    

Formula A>0?0:1    

A CalcLogicDigital  

4.6.4.2.2 COMMUNICATION ALARM

If at least one device is good, radio link says good.

If all devices fail, then the link says bad. If you DISABLE a device, and at least one other device is good, then the RADIOLINK says good.  If you DISABLE all devices, then the COMPORT goes to DISABLE and RADIO LINK says FAIL.

The crux for the following is two Calc blocks with which OR the logical NOT each input from a DEVSTS System Tag with the exception being input 20 of the main calc block is input from the secondary calc block which does not use a logical NOT.

Tag Type                Calculation (discrete)

Tag Name                RadioLink

Description               Radio Communication Link still working

Evaluate frequency    1  Second

State 0                    RADIO FAIL

State 1                    GOOD

State 2                    NotUsed

Formula   !A||!B||!C||!D||!E||!F||!G||!H||!I||!J||!K||!L||!M||!N||!O||!P||!Q||!R||!S||T

(notice there is no NOT for T)

A                Port2Device1

B               Port2Device2

C               Port2Device3

D               Port2Device4

E               Port2Device5

F               Port2Device6

G               Port2Device7

H               Port2Device8

I               Port2Device9

J               Port2Device10

K               Port2Device11

L               Port2Device12

M               Port2Device13

N               Port2Device14

O               Port2Device15

P               Port2Device16

Q               Port2Device17

R               Port2Device18

S               Port2Device19

T               RadioLinkd20to25

 

 

Tag Type        Calculation (discrete)

Tag Name        RadioLinkd20to25

Description     Radio Communication Link still working devices 20 to 25

Evaluate frequency 1 Second

Keep Previous Value No

Initial Value   0

State 0                 RADIO FAIL

State 1                 GOOD

State 2                 NotUsed

Formula         !A||!B||!C||!D||!E||!F

A               Port2Device20

B               Port2Device21

C               Port2Device22

D                Port2Device23

E               Port2Device24

F               Port2Device25

 

Create 25 of the following DEVSTS system tags

 

 

Tag Type        System Point (discrete) (really a DEVSTS type system point)

Tag Name        Port2Device1

Description     Port 2 Device 1 Status

Comport Number, Unit Number 2,1 (1-12,0-255)

Read Only Yes

Keep Previous Value No

Initial Value 0

State 0                 OK

State 1                 BAD

State 2                 Disabled

State 3                 NotUsed