Siemens S5 115 timer values

[CRMCC]

I have recently started a new job and to my surprise the site has quite a few S5 plc's. I had the official training with siemens over 20 years ago and have not seen a S5 for the last 13 years. I am now at work attempting to alter a timer value on a machine but get a message saying user program in eprom. I thought I had done this previously where the program is on eprom, when the CPU has been powered off the program is loaded from eprom but once it is running then online edits can be made and timer values could be edited. I hav unplugged the eprom and the machine is running as normal but still unable to edit the timer value. Am I remembering this operation correctly or am I mistaken? I have resorted to loding the program from the PG to allow me to edit the timer, the eprom can be re-programmed with the correct values at a later time after the commissioning has been completed, but there has got to be a better way. Any advice would be greatly appreciated.

 

[Liam Moran]

There are many different ways of manipulating timer values on S5.
The timer value can be hard coded using for example KT100.1 which would be 100x0.1s, or 10 seconds. It would not be possible to change this value once the program is burned onto EPROM. To enable the values to be changed from an HMI or other device the best solution is to store these time values in a Data Block, for example DB11. To use the data word in the program you must first call the Data Block where the time setting is stored, and then use the data word as the timer preset. If you want to be able to edit this Data Block then leave it in the RAM of the CPU, not on the EPROM.

 

[Liam Moran]

In the event of power loss in conjunction with battery failure, this Data Block will not be saved.
There are a couple of ways to regenerate the Data Block, one is by using the GDB command in a Function Block
and then loading default values into the data words.

LKF +100 !Declare length of data block
GDB 11 !Number of the data block to be generated
L KT 100.1
T DW 0
and so on.

I have not done this in years (Maybe 20) so I may not be correct above as regards syntax.
I do have some sample code that I can send to you if you want.

 

[CRMCC]

Thanks for that information, i did know DW could be used but on this timer they have used KT060.1, my memory obviously is not as good as yours, unless the programs I have edited in the past were all running on the CPU, allowing me to overwrite with a block transfer. I will look at modifying the timer to use a DW, I think the original part of the program has a DB for timer values so I can probably use the same DB.