for history sake here is a good post about POS from 2005
Hi Matt and BJ, I know what you mean about TCP/IP reliability in legacy equipment environments, most companies are STILL RUNNING FLAT NETWORKS! With thousands of hosts! There are a few options to consider here one is RS485, this protocol is very popular in manufacturing and device control environments. I have experience in RS485, RS232 and converting them to TCP/IP as well but the crux of the matter is at some point these legacy protocols MUST be converted to TCP/IP luckily they do sell RS485 PCI boards, but try to make one work in Linux or UNIX). The good news is there are plenty of reputable companies selling products that do RS485/RS232 and even RS422 to TCP/IP conversion. The only limitation is generally 32 devices per box on RS485 for some reason. I have no experience with RS422 unfortunately, it was very popular as well. As far as printers are concerned I am working on piece of Postal equipment with a Moxa RS232/RS485 to Ethernet converter and a separate RS232 to USB conversion as we speak. The Moxa device creates virtual com ports so that you can assign separate IP addresses to each device and will treat them as separate entities. I was working on this project just today as a matter of fact. I have had plenty of success in the past but I could not see any action from the Postage Machine as far as RX TX on the Moxa. I think I do not have the correct pin-out on the RS232 side but I was only 3 hours into the project and building my own cables, so more research is needed. I am not sure about the old Centronics printer to anything conversion other than RS232 to Centronics. One of our technicians was able to purchase a "black box" to perform the conversion, here you would definitely be limited to distance, again on a Postage Machine. This is why I am trying to convert to USB/RS232 and Ethernet so that our customers are not locked into buying a separate (proprietary) over priced printer just to run postal accounting reports, I would like to afford them the opportunity to send it to an existing USB or network printer as a courtesy to our customers. When it comes to connecting to RS232 you are limited to about 100 feet in my experience before you begin to experience severe dispersion and jitter in the signal, Ethernet being the same, 100 meters before it must traverse another switch or repeater but can only happen so many times before the delay becomes a problem, with the exception of LRE and fiber optic (another topic for a different day). RS485 can be ran as far a 3,000 feet from what I have read, such as a factory floor or assembly line but I have not had the opportunity to test this and scope the signal. It is a simple bus configuration and is only two wires, kind of hard to mess that up. In cases like this, shielded twisted pair I.E.(Cat 5 STP MUST be used with SHIELDED connectors on both ends firmly grounded at the connectors and MUST BE AT THE SAME GROUND POTENTIAL) but this is THE most popular protocol used in industrial applications. For sensors, servos, controllers etc next to RS422, (a Sony Protocol). BJ’s question, “been working on how to allow badge readers, Touch Screens, printers, scanners and scales to interface to ofbiz and not be tied to serial, parallel ports. two versions, are network aware using Ethernet. the other is Wifi aware. ofbiz entity would then define the list of IP and ports they map to for functionality. any input?” BJ, I could definitely be wrong here but it is my opinion that everything is moving to USB as far as connectivity to the PC for POS peripherals. If you order a new Dell you must ask for PS2 interfaces specifically, otherwise its all USB, and trust me on this one (recent experience) a keyboard wedge scanner and a USB converter is NOT reliable! I have seen loads of various USB to Ethernet converters and this could be used to our advantage in the appropriate environment. I have found that in many board meetings if you mention WI-FI the frowns begin to appear around the table when it comes to sensitive data like I.D./personal data being sent over a WI-FI connection. HIPPA is spreading like a rash even in HRS.(I believe I have a workaround for this if it is not to memory or processor hungry. Speaking of HRS I have some screenshots from an application designed for higher education and there are a lot more parameters involved when it comes to HRS than I would have ever imagined these screen shots definitely make yo realize just how much there is to HRS. If anyone is interested I will e-mail them to you for examination please feel free to e-mail me direct at dkey at card-x.com When we are talking printers, scales, Scanners and the like, JavaPOS can be of great help, I realize that they are not entirely up to date but these are the only resources available for standards based interfaces, which I believe is the future. Most are serial in nature, I have often thought of using Infrared to connect such devices to a POS unfortunately I have not found a vendor who builds such an animal, but I do have a brother who engineers just about anything electronic. I always try to make my POS installs as neat and tidy as possible but there are just too many wires and I cringe at even my best installs. I was not aware that touch screens would be a problem, I have no experience in PC based touch screens. I was under the impression that they were handled just like a mouse and keyboard. PLEASE ADVISE IF YOU KNOW DIFFERENT especially in a Linux invironment. I have done extensive research on I.D. “Badge” readers and could definitely use some help on your side with this as far as Java goes. Most badge readers are either RS232 or USB, but we both know these have their limitations. The company I “Currently work for” has two sides, one being postal solutions and the other, I.D./POS solutions. I can definitely point you in the right direction as far as I.D. badge solutions go, as well as my experience with smartcard I.D. deployments if that is what you are looking for. I can point you to the most cost effective microprocessor cards on the market and why they are one of the best cards available. I am currently waiting for Philips USA to open on Monday as they have been closed for the past week and I have been assigned to a technical rep for clarification on which readers go with which cards and what type of communication interfaces are available for each etc. Philips is at the forefront of Smartcard development along with Samsung, they (Samsung) currently have the quickest read/write time 115 kb per second but they are very expensive. This is definitely the way things are heading (IMHO), along with RFID tags for inventory and product tracking, something I would like to see in OfBiz at some point. I recently viewed a report on T.V that over 40% of class 2 prescription narcotics arrive at their destination as counterfeit products, having being replaced by thieves. Definitely food for thought when it comes to inventory control. Sorry for the Mini Novel I just want to help as much as I can since my work keeps me away from the Java books so much. Hope this helps, Dale Bilgin Ibryam sent the following on 9/10/2007 4:54 AM: > Hi everybody, > sorry for the long post, but please read ahead and tell me your opinion. > I have to implement a web based pos system for a restaurant. > Before start coding i will be glad to hear your opinions and advices. > > First of all i decided to go web-based instead of using existing ofbiz POS > because it does not cover all my needs. In the restaurant i need: > 1) To enter the registered customers for order payments. > 2) To edit orders. > 3) To do Returns. > 4) To visualize tables, seats, to do table reservations... > > I decided to do a new ofbiz component, with UI similar to pos (but html, not > swing) for easy using with touch screens, that allows order entering in a > fast way (similar to order manger but with possibility to enter orders in > lesser clicks). > > Is there someone that has experience in this kind of things that can give me > some advice? Do you see any possible difficulties and drawbacks in doing a > web based pos system? > > About the implementation: > The other thing that i have to care are the tables and people setting there. > For tables i can use Fixed assets, but i cannot decide how to handle/group > customer orders. > 1) One way to go is to create a separate sales order for every person, so > everyone can pay only for his/her products. > Then i can group the orders for the table with a work effort. I need to > group the orders, because i need all the time to calculate the total for the > table, the total product list and the complete all the orders for the table > with one click, if needed. > Do you think that manipulating lots of orders could work fast enough, > because for example the order creation in ofbiz is heavy_weight/slower than > other operations? > > 2) The other way to go is to create only one order per table at a time and > to create separate ship groups for every person. This way i can assign > parties to ship groups, but it is NOT possible these parties to pay only for > their products in the ship group. Is it possible somehow? This way i have to > create, edit , complete only one order for all the people setting around a > table at moment. > > (In general my questions are: is it a good idea to do a web based pos and to > manipulate lots of orders at the same time (like one order) regarding fast > working needs of a pos system ?) > > Please advise and thanks in advance. > Bilgin Ibryam
