Just been given a Multi Panel from Saitek amd i’m wanting to use it on PMDG and with linda i have the modules. My question is what do I select for alt, vs, ias, hdg and crs inc and dec value as the saitek switches between the modes and  has one knob to change the values

The LINDA Multi and Radio Panels work with the default AP using FSUIPC offsets. Aircraft like PMDG do not always conform to offsets. It is not possible to assign the PMDG module functions to the Multi panel. 

So does that mean I'm wasting my time if I try to program them up or do the buttons work ok

Probably. If you are a programmer you could look at the LIB-Saitek.LUA code and customise it for your purposes. The code was written by someone with more knowledge than me. It is complicated by the need to handle the different positions of the rotary switch. You would need to untick the Saitek Panel checkbox in LINDA Setup to activate the LUA implementation.

Alternatively you may wish to try SpadNxt and disable the Saitek panel in LINDA Joysticks. I don’t know whether this would work and it is unlikely you can use the LINDA PMDG functions.

I had some success at creating linda functions for multi panel.

All the lua code I create are located in the user.lua of each aircraft that I modified.

First you need to write some functions to fetch information to display on the multi panel. You can use the same function names as the one in the original linda code as the function in user.lua have always precedence over the original linda code.

to display to the multipanel, you need to rewrite the following functions. You can start by copying the original code into the user.lua of the plane you want to modify then change a few lines.

 - getALTvalue()

 - getVSvalue()

- getSPDvalue()

 - getHDGvalue()

- getCRSvalue()

you will find the original functions around lines 5270 of the common.lua files of the original Linda code. You can look at the module created by Linda authors for the PMDG as you can often identify which code can replace the original one.

Now for changing the value its a bit more coding but this time you want to recopy and modify the code from the Saitek library as mentionned in the post above. There is one function to increase and one to decrease. In my case I also created a function for larger increment that I use with the shifted mode offered by Linda. I also fuzzed a debouncing code to avoid the double increment or decrement that often arrises.

I have such code for the Majestic Q400, A2A Piper Cherookee, DA60 and some others but nothing for PMDG as such.

Send me a p.m. if you want an example of this code.