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This manual documents the functionality available in the MacroView Symax 802.3 Communications Driver. The Symax 802.3 Protocol is an ethernet based protocol developed for the Square-D Symax range of programmable logic controllers. The driver's executable name is symax and is supported on the operating system platforms listed in the table:
Platform
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Processor Type
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Windows 2003
Windows XP
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Intel x86
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Redhat Fedora 1
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Intel x86
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Contact your MacroView supplier to discuss availability of the driver on other platforms. The driver's ethernet communications layer is built on the pcap library functionality that is available on a variety of operating system platforms, so porting to another MacroView supported operating system that has good pcap library support is not seen as a difficult task. Note that the pcap library support on the SCO operating system is poor especially considering the restrictions as to which ethernet cards allow promiscuous mode access to network traffic.
Note that this symax driver is a ground-up re-implementation of the Symax 802.3 protocol and is not related to previous MacroView implementations such as the sqde and sqdred driver versions. The major features of this symax driver implementation include:
| • | Enhanced PLC Model (blocks are scanned based on polling period specifications which gives finer control over network bandwidth usage). |
| • | High performance (support for multiple outstanding requests per PLC station increases the effective communication throughput). |
| • | Linux and Windows support. |
| • | Built on a portable communications infrastructure (libpcap). |
| • | Not reliant on specific ethernet card models |
This symax driver implementation does not support the following functionality areas:
| • | Redundant communication paths. |
| • | Handling of unsolicited messages sent to the driver. |
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