Hi Mark, I currently have a prototype of ModIP, a TCP/IP modbus slave device that I'm developing.
I think that Modbus over TCP provides an excellent robust interface for external I/O devices. The biggest hurdle I'm trying to overcome at the moment is the form factor. I've gone from a traditional PLC style to a miniature CPU core board that plugs into various I/O motherboards, to a Arduino form factor, to a daisy chain setup. Still working on it. :) Cheers, Peter. On 29/02/2012 10:24 PM, Mark Wendt wrote: > Peter, > > No problem. You brought up another tid bit to add to the conversation. ;-) > > Mark > > On 02/29/2012 06:17 AM, Peter Homann wrote: >> Hi Mark, >> >> Oops, sorry I misunderstood the conversation. >> >> Cheers, >> >> Peter >> >> On 29/02/2012 10:15 PM, Mark Wendt wrote: >> >>> Peter, >>> >>> I was referring to Kirk's not seeing port 1502 after he assigned it in >>> the loadusr statement, and how the OS handles ports above 1024. >>> >>> Mark >>> >>> On 02/29/2012 06:07 AM, Peter Homann wrote: >>> >>>> Hi, >>>> >>>> Port 502 is assigned to Modbus, so that's what slaves should use by >>>> default. >>>> >>>> Cheers, >>>> >>>> >>>> Peter. >>>> >>>> On 29/02/2012 9:40 PM, Mark Wendt wrote: >>>> >>>> >>>>> On 02/28/2012 05:21 PM, Kirk Wallace wrote: >>>>> >>>>> >>>>>> ... snip >>>>>> >>>>>> I think I know a little more now. I was able to bring up >>>>>> "loadusr classicladder --modslave" (I didn't know the rt component had >>>>>> to be loaded too). My netstat returned the same result above with >>>>>> "0.0.0.0:9502". I then did a ifconfig to find my network computer's >>>>>> addresses with 192.168.1.10 (eth0) and 127.0.0.0 (localhost) being >>>>>> listed. I nmap both addresses and found port 9502 open on both, so it >>>>>> seems by default, "--modslave" will listen on all addresses (two in this >>>>>> case), with "all or any addresses" being called out as "0.0.0.0". >>>>>> http://en.wikipedia.org/wiki/0.0.0.0 >>>>>> >>>>>> If I use "loadusr classicladder --modslave --modbus_port=1502" netstat >>>>>> sees port 1502 as listening, nmap doesn't see it whereas it did see 9502 >>>>>> previously. My guess is that as any ports above 1000 have lighter >>>>>> restrictions, maybe ports above a higher value are handled differently >>>>>> too, so 1502 doesn't show where 9502 does. I guess I have more work to >>>>>> do. >>>>>> >>>>>> I haven't tried connecting to the LinuxCNC slave with a master yet. >>>>>> >>>>>> >>>>>> >>>>> Actually, ports 1024 and below are considered "privileged" ports. Any >>>>> ports above that are considered "non-privileged" ports and are all >>>>> treated the same. Do a 'netstat -a | grep 1502' and see if the 1502 >>>>> port shows up. >>>>> >>>>> Mark >>>>> > > > ------------------------------------------------------------------------------ > Virtualization& Cloud Management Using Capacity Planning > Cloud computing makes use of virtualization - but cloud computing > also focuses on allowing computing to be delivered as a service. > http://www.accelacomm.com/jaw/sfnl/114/51521223/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- ----------------------------------------------------------------------------- eStore: http://www.homanndesigns.com/store Web : http://www.homanndesigns.com ModIO - Modbus Interface Unit email : [email protected] DigiSpeed - Isolated 10Vdc I/F Phone : +61 421 601 665 TurboTaig - Taig Mill Upgrade board ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
