Siemens S7-300 STL JC

[elons_nephew]

Hello,
I am still new to STL. But from what I understand is the JC mnemonic should jump if RLO = 1. If we review both pictures the M0bf RLO = 1 in both conditions yes in one instance it jumps and the other it executes the lines below it. I'm not sure what I am missing here, any input would be muchly appreciated.

 

[L D[AR2P#0.0]]

You need to look at the RLO before the JC instruction as the RLO is set true when the JC instruction executes if the RLO beforehand is false.
Click on the JC instruction and press F1 to get the help on the instruction.

 

[cardosocea]

Is it on a running machine that changes that RLO bit frequently? Or is the machine static? I'm just wondering whether this is the software catching up to display the values on the instructions it jumped.

Logic runs a lot quicker than the comms and TIA portal so I can understand that if that condition changes regularly that it may cause some hickups on the display to the operator.

If you have the ability, create some test jump that is controlled solely by you to see if it's replicated.

 

[elons_nephew]

It is static, it is a redundant system. we can run one fan or the other. The two images I uploaded are showing the running of one motor and then the other.

Is it on a running machine that changes that RLO bit frequently? Or is the machine static? I'm just wondering whether this is the software catching up to display the values on the instructions it jumped.

Logic runs a lot quicker than the comms and TIA portal so I can understand that if that condition changes regularly that it may cause some hickups on the display to the operator.

If you have the ability, create some test jump that is controlled solely by you to see if it's replicated.

 

[elons_nephew]

Thank you very much. This is very helpful

 

[L D[AR2P#0.0]]

You need to look at the RLO before the JC