Welcome to EpoS Wizard!
OK, so I'm a complete newbie to this forum, and a "happy-go-lucky" fixer to my single terminal in a small, but busy shop. Situation is that I have a 4-year old ER420-M that was bought for my shop before I took it over. The till was good, but underutilised, so I went over to a proper barcoded system of sales about 3 years ago, alongside a memory upgrade to give me the potential of 8000 PLUs. Using SamStock to keep track of sales and orders for this general store, I realised that I was going to quickly run out of time to maintain the system inside trading hours, so I purchased a second SamStock license and used that to work on the data after hours. The shop typically has 2500 - 3000 lines which are primarily the mainstream grocery stock, some are EAN13 internally generated codes.
Up to now, the main problem has been a) keeping track of the ever-changing PLUs against products, and b) ensuring that the data files are robustly kept synchronised between the shop and home office that run the two SamStock licenses. Everything appeared to be going smoothly, albeit that SamStock has a few glaring issues with the way it handles stock control in a retail environment, until last weekend....
Suddenly, and without warning, the SamEvent routine to download PLU changed data back to the till (prior to daily upload of Z-data at close of business) has decided that it doesn't want to download any more. In all of a panic, I checked to see how many PLUs I had on the ER420. Around 3500 appeared on the memory report under the Service mode, so I discounted that as a problem, although it has been at the back of my mind that the allocation of 8000 is not going to work forever. The memory allocation still shows approx 71k max versus 70k used, so I haven't altered anything there since 3 years ago. The till still works, and the programming functions for PLU data (prices, deletion, addition of items, etc.) all work via the keyboard and the ER420 PC link utility.
The problem in SamEvent is that it just reports a "-999 exception" error in the error log when you try to either send changed PLU information (even just price changes) or send the full PLU file. Absolutely no issue with receiving data from the till, such as polling end-of-day sales data and Z-reports on the financial data from the till. Until now, there has been no issue (other than a single problem with a damaged RS232 lead some time back) with any of the end-of-day processes. The PC is a stand-alone unit dedicated to the till for SamStock, as well as spreadsheets for other admin tasks. It doesn't go online, it doesn't have anything poked into it, other than my well-virus-scanned USB stick.
Has anyone seen anything like this before? I know it is more likely to be a SamStock issue (and that is bad news.....), but I have had doubts about how long the ER420M can go before a full-blown memory clear is going to be required to purge obsolete PLUs from the memory, and have considered a duplicate ER420M or even a SER7000 replacement. The hassle of re-programming everything again is a big worry, to the extent that if this is a SamStock issue, I may investigate another route (Sharp?) to a till that communicates sensible data into a home-grown database. 
Well, I managed to sort this one out this morning. It was the SamStock database.
What had happened was that the main product table had managed to get an invalid character overwritten to the till EAN field on a product that had been changed for price on Saturday afternoon. I don't know how this had happened, but it was easy enough to edit again within the SamStock maintenence screen. The person responsible does not know how she managed to click on the EAN field, as you would not normally go anywhere near it, for anything. I thought I had locked the EAN to the PLU, but obviously not well enough.... 
seen it a million times
the database is based on excell spreadsheets.
if, a comma appears anywhere in the file, this pushes all the other fields one position out
stay away from apostrophes, commas, inverted commas back slashes and forward slashes
i would suggest that you use the dealer logon to "check structure" and "pack tables"
to highlight any other issues - [dont forget to shut down sam event first AND BACK UP THE DATA DIRECTORY]
or you could export the whole product file to excell and use the find and replace tool to get rid of the above characters.
you are the first person i have ever met that went to the expense of 2 licenses - why not just use team viewer or logmein to access the pc containing samstock via broadband?
Thanks for the candid advice. I've been thinking that I need to get a bit more involved in the database side of things, as the SamStock system, brilliant though it is, is not great for the sort of retail outlet that I run. The reporting schemes are clunky in the extreme (for any sort of shop) and lack any real understanding of what matters for stock control and ordering when you have got little control over supplier substitution, etc. etc.
The reason for the two licenses is that I wanted complete independence to work away from the shop PC - including not disturbing the dongle on the back of the PC every night. That PC has the attributes of being a) tucked away awkwardly, and b) not networked in any way or form. The latter attribute comes from my previous occupation at the leading edge of automotive calibration and control systems, so I'm a bit paranoid about external interference (you don't want external influences when you are piling along a mountain road with a sheer drop........) and losing data. The data I have accrued for the shop so-far is already too important to loose, and gets more important each day. So although I am quite critical about SamStock, I still recognise it as important enough to my business to invest in a second license (painful though it is.....). If I can make SamStock work better for my business, then all the more justification for that license!!
As it happens, I have just done this morning the second method to checking the tables that you mentioned (using the CSV export into a spreadsheet to analyse the data formats) and, yes, found loads of dodgy commas in the product descriptions, all pushing the data around. That's how I found the problem causing my main download issue, analysing the product codes and EANs for non-integer values with a filter. I wished I had done this before.... 
Would logging-in as an admin, and packing the tables improve the reliability of the database, or do you think it will just highlight problems further? I have a particular concern about the way that the main product table links to supplier ordering data, as I know that this is one area that glitches on a week-by-week basis, i.e. often find products do not order because the supplier order information has unlinked from the PLU (just disappeared, not overwritten, from one hour to the next whilst working on other PLUs). Hence I have to run a regular report to highlight PLUs that are below the order trigger, but have no order scheduled.
Thanks for your help, once again, it's much appreciated.
go to the dealer tab [located between the window menu and the about menu] and from the database utilities menue choose check structure first then run pack tables this is a bit like registry cleaner - but for samstock
IT IS IMPERITIVE THAT YOU SHUT DOWN SAMEVENT AND MAKE A COPY OF THE DATA DIRECTORY BEFORE RUNNING THESE UTILITIES
