Issue link: https://iconnect007.uberflip.com/i/1091269
MARCH 2019 I PCB007 MAGAZINE 43 ment of Mentor Graphics/Valor and has hard- ware that can be purchased from them. The OML carries on the long-standing tradition of ODB++—the PCB design communication standard from Valor. No information has been presented if OML conforms to either MAP or SECS II standards. The OML Community website [8] describes how, "OML features bi-directional data flows for shop-floor data creation as well as process control, all through a single, standard format, language, and protocol. Any creator or con- sumer of OML data will require the develop- ment and support of just one standard inter- face rather than the current need for many dif- ferent interfaces." One presentation [9] explains, "OML request/ response messages provide OML applications with real-time control of equipment or pro- cesses at the shop-floor. These messages are bi-directional. Control can be initiated by the OML application toward an OML process on the shop floor (e.g., specific equipment or lines can be stopped). Control can also be initiat- ed from the OML shop-floor process toward an OML application. For example, the shop-floor process can check if a specific PCB can enter specific equipment every time a PCB enters the process." OML Data Formats OML uses the JavaScript Object Notation (JSON) standard to represent each message. The use of JSON in the software industry has rapidly increased year on year with the format now widely used in most web-based technol- ogy and across the internet in general. For ex- ample, JSON can represent the same data while using significantly less space than XML, which means performance gains. However, like XML, JSON is still human-readable and can repre- sent complex data. JSON is easily compressed to reduce size for further efficiency. JSON is a fully open standard with mature future sup- port in most major programming languages and platforms. The complete OML users guide and standard can be found on the OML Com- munity website [8] . Look for this standard to gain momentum in the industry as Mentor Graphics/Valor has been acquired by Siemens and is added to their large pool of MES, ERP, PLM, and automation products. CFX The IPC Connected Factory Exchange (CFX) initiative seeks to create an M2M protocol for SMT manufacturing. CFX is based on the old SMEMA 9852, but is now called the IPC- HERMES-9852. CFX uses the reliable TCP/IP communication protocol and XML tagged data messaging based on advanced message queu- ing protocol (AMQP). Over 43 companies have joined this working group. The Hermes stan- dard uses TCP/IP to permit all stations on an SMT line (e.g., printers, conveyors, placement machines, AOI systems, reflow ovens, etc.) to talk to each other. Hermes employs expand- able XML data structures to transmit informa- tion like board IDs, conveyor speeds, and cir- cuit carrier dimensions. Each board must be identified only once by a Hermes-compatible machine at the start of the line. With its publi- cation as an open standard, the Hermes stan- dard will be available to all SMT equipment vendors at no cost. And since the protocol was designed to be expandable, users can pass ad- ditional information down the line. You can find the list of company supporters and more on the IPC-CFX website [10] . IPC-2541 IPC's 2-13 Shop Floor Communications Sub- committee brought together leading software developers, machine vendors, assembly equip- ment manufacturers, and their customers to work on the development of a new IPC stan- dard to meet the current and future needs of the industry that will fill a gap identified by the group. This new standard will provide unifor- mity of data protocols that will allow ease of M2M communication. Messaging as the Elements of a Network Protocol Semiconductor fabricators like to avoid writ- ing custom software to fit all the idiosyncra- sies of individual processing systems. So, HP