Using Instrument I/O assistant

[dformica]

I am using Instrument I/O assistant to communicate via RS-232 to a gas analyzer.  The analyzer uses binary protocol, starting with a STX (start of text) command, and then the command (read value, calibrate, ect. ect), with a checksum value for the remaining bytes sent.

I have tried the Query and Parse with no success using binary.  All that I receive is timeouts.

I have broken the command down to a write and read, and inserted write commands for each byte in the command string (STX, command, checksum).  This has been successful and the analyzer has returned valid data.  I have parsed the data and have broken down it into tokens by manually parsing it via the read command.  The command I am sending is a "system status", 0x01, which returns a 32 byte data value of the current gas values.

The vi I want is simple.  I want to read this command every second and display it on the screen, as well as write the coresponding tokens to a *.csv file.  I understand the basic layout of the vi.  My question is what inputs are needed to the Instrument I/O assistant to enable the command string I've created from the "write" command?  Do I change the Instrument I/O assistant to a vi, and then wire in the required inputs?  What I am doing does not work.  I am getting various errors from the vi, timeouts, ect.  How do I make the Instrument I/O assistant that I have created just cycle?

Use of a RS232 interface to Gas analyzers is common, with some interfaces being propriatry, others conform to the "AK' standard which is a set of commands for gas analyzers.  This instrument is old and propriatry, but I have other intruments in which I will need to use the same methodology (Instrument I/O assistant) to establish a User Interface.  I believe this to be the correct method.

I have taken the Labview Basics training I & II last year.  However, due to project scheduling my company has only requested LabView development recently, so I'm a little bit rusty but recalling quickly.

[Albert.Geven]

The best you can do is to use the basic serial write and read vi to build some subvi's that do what you want. The isnstrument IO assistant is good for trying.

[pflores]

As with most Express VI's (all the ones with the light blue border and the configuration wizards), the Instrument I/O Assistant is great for setting up a quick, easy application. As you demand more functionality or flexibility, it is usually better to abandon the Express VI's and use the standard VI's. All Express VI's are just built on other system VI's, after all. A great way to see what VI's are running underneath the Express VI is to right-click on the Express VI and select Open Front Panel. This will convert the VI to a standard sub VI, allowing you to access the block diagram and see what VI's it is calling.

As Albert suggested, the Example Finder is a great source for examples to help you on your way. You can find these shipping examples in Help->Find Examples... then browse to Hardware Input and Output->Serial.

Good Luck!