On 9/24/2011 11:23 AM, Kirk Wallace wrote: > On Sat, 2011-09-24 at 10:14 +0300, Viesturs Lācis wrote: > >> Hello, gentlemen! >> >> I would like to ask, if anyone could share their experience with Omron >> V1000 VFD. More specifically, I am interested in getting the drive >> communicating with EMC through Modbus. Is there anything specific to >> know or to avoid? >> >> Thanks in advance! >> >> Viesturs >> > It has been a while since I played with Modbus, but Modbus is a standard > for communication and partly the internal working of devices. The > communication may be through a serial port or Ethernet. The internal > part is a loose register configuration. Each device will need a custom > driver covering the register assignments. Documentation for the device > will be needed. Serial and Ethernet is in user space, so is non-realtime > which might be fine for a spindle. Checking for the spindle speed status > might be an issue, there should a HAL component for this. > > Basically, one should start with one of the existing drivers and modify > it to match the registers of the device in question. There are a few > links that started covering VFD Modbus, but didn't get too far: > http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?VFD_Modbus > > There is a subtle difference between the different sample drivers. I > seem to recall the difference is in where the sources are and how to > compile them, either as a HAL component or compiled in EMC2. > > I may be able to dust off some of the little gray cells if more > information is needed. It would be a good thing if I or someone else > would bring the wiki up to date on this. > > Another issue is that Modbus is rather old and may not be useful > sometime in the future. > > Off the top of my head, real-time might be had with a parallel port > connection to an AVR/Arduino to convert to Modbus, which could solve > some of the communications timing issues, ... or not. > >
Actually Modbus is quite specific in it's specifications. I do a lot of work with Modbus on various devices and if the protocol is properly implemented, there is usually not a "loose parts issue". Most major manufacturers connect quite nicely after deciphering their manuals on how to configure the Modbus interface. (The clarity of documentation is usually the issue, not the Modbus protocol itself) Modbus runs on RS232, R422, RS485, and Ethernet so I think it will be around for a long time. It has become more popular over the last 10 years. PS.. I read that Utterpower article before you quoted it.... apparently a lot of us think in a similar fashion. :-) Dave ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2dcopy2 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
