VISA Read Timeout and VISA Write not working

[airic001]

I'm writing a program that sets a triangle wave pattern voltage (using Triangle Wave VI) to a DC power source (GWInstek PST-3202) through a RS-232 connection.  I know my instrument parameters are set up correctly because I've been able to control this power source using a different VI with the same parameters.  I also know I am connected to the power source because I can talk to it using MAX.  I have a string indicator before my VISA Write statement that shows me the command being sent to VISA Write.  It shows the correct syntax for setting a voltage on this instrument.  However, when I run the VI, the voltage is not changed on my instrument, even though the correct command is sent to the instrument.  After the VISA Write operation I have inserted a VISA Read function in order to read the newly set voltage from both a numeric and a waveform indicator.  Using the Error Out cluster I am able to see that there is a timeout error from VISA Read.  I thought perhaps I needed to clear or flush the buffer after each Read statement, but that didn't work either.  I'm stumped as to why VISA Write isn't writing to the device.  I have included my VI below, as well as the initialization subVI for the power supply.  

[RTSLVU]

I am going to go out on a limb here and suggest you might need some sort of flow control in your serial settings.

Have you turned on the trace to see where the error is first occurring?

[Dennis_Knutson]

I don't see anyplace where you are appending a termination character to your write. Why don't you attach the code that works?

[airic001]

I have attached a code that works.  I will look into the termination character issue.

[crossrulz]

Yep, you need to append the End of Line character to the end of your command.  And for your read to work properly, you need to request the data.  That requires a querry command to be sent.  Look closely at the differences in command and communication structures between your working VI and your mod.