Step 7 "OPN"

[cottagewood]

Hi

I'm trying to decypher some step7 code which all seems pretty straight forward except that there are several instances of OPN DB100 but no transfer of move commands associated with it, for example
Network 1
OPN DB 100
AN "23K1 Kneader Estop"
S M 51.5
= M 16.1
A M 100.1
R M 51.5
R M 24.1

and further on

Network 12
OPN DB 100
A M 104.1
AN DBX 207.0
S DBX 207.0
A DBX 207.0
AN M 102.5
S M 104.0
O M 166.3
ON DB10.DBX 13.5
OPN DB 100
S M 67.1
A M 67.1
= M 18.2
ON "KneaderGuard Common alrm"
ON "KneaderGuard Sensor1"
ON "KneaderGuard Sensor2"
ON "25K6 Crammer saftey OK"
ON "26K6 Crammer 2 saftey OK"
ON "261K6 Crammer 3saftey OK"
S M 67.2
A M 67.2
= M 18.3
A "KneaderGuard Common alrm"
A "KneaderGuard Sensor1"
A "KneaderGuard Sensor2"
A "25K6 Crammer saftey OK"
A(
ON M 113.5
O "261K6 Crammer 3saftey OK"
)
A(
ON M 106.6
O "26K6 Crammer 2 saftey OK"
)
R M 67.2
R M 18.3
R M 26.3
A M 100.1
R M 67.1
O M 166.2
O M 26.2
= M 67.0
O M 67.2
ON "23K7 Control On"
ON "23K1 Kneader Estop"
O M 67.1
O T 11
O T 121
O M 69.1
O M 71.1
O
AN M 166.4
AN M 50.0
O
A M 67.2
AN DBX 219.0
R DBX 207.0
AN DBX 207.0
R M 104.0
A M 104.0
= "28K9 Enable Keader"

Can anyone tell me what the relevance of DB100 is

Thanks

 

[krk]

as an example......


Network 12

OPN DB 100
A M 104.1
AN DB100.DBX 207.0
S DB100.DBX 207.0
A DB100.DBX 207.0
AN M 102.5

 

[Jeebs]

OPN opens a DB, any reference to DBX, DBB, DBW, DBD without specifying any other DB, will be made towards the currently open DB.

You should take care though.
Adding a simple A DB101.DBX12.4 for instance will open DB101 until another DB is specified, this will result in unexpected behavior as the next DBX, DBB, DBW, DBD references will point to DB101 and NOT DB100.

It smells of S5 code.
You should try to fix it.
Doing it like that also makes it impossible to use symbolic naming.

 

[cottagewood]

Ah yes, I missed that
Thanks

 

[uptown47]

If you go online in STL and look in the DB1 column. This will tell you the currently opened DB.

Any reference to DBWx etc will then refer to the DB listed in DB1.

;-)