Omron addressing

I have been given an Omron program to diagnose on a new to me PLC CS series. Can anyone tell me what the W addresses are used for?

I can't seem to open the manuals on the Omron site.

Many thanks

Derek

W memory area is a freely addressable 'Work' area within the PLC, which can be used for both Read and Write operations.
They can be addressed as bits (W0.00) or as words (W99).
The values held in this area are cleared on power-up, or when changing the PLC mode. (ie Run to Program, and vice-verca).
The area is 512 words in size, W0 to W511.
Hope this helps

Work area is internal bits only. Be careful using them if a SCADA system is to be used over the top. A lot of SCADA systems cannot address the work area.

W bits are for use as internal IO, Omron use CIO for Card status,Config and diagnostics. W bits will not be used as any system IO so from the point of view of the the programmer won't find himself programming in system IO areas if he uses W bits for all of his work coils.