Saphum

Spent some time over the weekend on an Ifos master control program targeting TINI. It’s a Java app wrapped around a tiny [sic] built-in web server and works great so far. Well, I should qualify that: it works great until I run it on the TINI. Being Java (supposably¹ cross-platform), the program can be developed and tested on my Mac, where it’s spiffy and quick. On TINI, however, there are two major issues:

• TINI supports only a subset of the Java 1.1.8 distribution. It’s a large subset, but it’s still a subset.
• TINI is much much much slower than I expected.

Up to now I’ve been controlling my Ifos slaves with a simple Modbus master I wrote in Ruby. In preparation for the move to TINI, though, I thought I’d better investigate Modbus master code actually capable of running there. jamod is the logical first choice, since it’s Java-based and fairly mature. TINI runs Java, and if jamod complies with the Modbus application protocol specification, everything should just work.

I knew it wouldn’t be long before the next wrinkle presented itself. There was some frustration of the “This should work now” variety, but eventually things worked out. I’ve adopted the Mac as my new development environment of choice (well, let’s call it my primary development environment; I just like it better than PCs or plain Linux so far), but I’m still trying to achieve parity on tool chains related to my various projects.

Still experimenting with the “master” portion of Ifos (the device itself being a Modbus slave), looking to replace/simplify the current communication path:

PC ⇒ USB-to-Serial (RS232) cable ⇒ my RS232-to-RS485 converter ⇒ Ifos.

The great advantage of this is unlimited flexibility; I can use just about any method to send data directly to the device, then process the response in myriad ways. Ruby has been the real workhorse here, and I rely on irb and my tiny Modbus master for most of this communication and control.