AB SLC 5/03 Forgets when Powered Off?

I recently did a program edit for a customer. He asked me to change the Presets in the PLC code and send an updated program.
This sounds strange.
It's a simple sequencer with 6 steps and timers. Timers are set in the HMI (PV600). I think these values would remain after a cold power down, but the customer states that the 5/03 reloads the defaults in the PLC program.
Is it true that the 5/03 'forgets'? Does it have a battery?

Another thing that struck me as odd - the original programer preset all timers to 32767, then uses a Compare instruction to test if the time is up. Why not just load the timer with the value from the HMI?

Edit: I think it's the code doing it. This 'simple' program has 12 subroutines! One of them initializes variables. If the 5/03 doesn't 'forget', then this is the problem.
I just wanted to ask the AB experts before making another trip.

You might want to check and to see if it is loading from a memory module on power up. This maybe over-writing your changes.

Steve

Answer From Ab

you can select this reminder tag value option from panelbuilder program for used PV550.
If you look at inside of your aplication with PanelBuilder32 than you can see at power-up side. You should select write to controler at start-up than chose use last terminal state option.

Both Steve and BlackMagic have given you good thoughts.

1. If the program is loading from the EEPROM after power up, you will always get the "default values" that you are seeing.

2. If the PV is writing values when it powers up, again, you can always get the "default values" that you are seeing.

3. It is also possible (as you identified) that the code itself is initialzing values on power-up. In that case, you just have to find where the "initial" values are coming from and change them there.

Bottom line - the SLC memory is retentive - unless you are actively writing from somewhere, cycling power will not change these values.

Marc

I have had this problem with panelviews on RIO. I wound up having to rewrite the HMI interface ladder code and the PView programs to use the notify and handshake bits to condition when the panelview write tag values are copied to the read tag values. It makes you have four addresses for every data item (read tag, write tag, notify bit, handshake bit). With other comms setups, you should be able to prevent the panelview from overwriting the SLC values by the method described by blackmagic.