Best way to send multiple serial commands

What is the best way to send multiple serial ASCII commands from a Compactlogix PLC to another piece of equipment? The issue is that the equipment (a chiller) can not accept more than 1 serial command at a time, and it needs at least 0.25 sec (according to the user manual) interval between commands.

At first I thought I was going to have to send only 2 commands. So I used a 1 second timer. The idea was to send the 1st command when the timer accum value was < 0.5 s, and the 2nd command when the timer accum value > 0.5 s.

Now it turns out I may need to send 5 or more commands. I guess I could do it the way I planned originally. Send Command 1 during accum < 0.5s, send Command 2 during 0.5 s < accum < 1s, send Command 3 during 1s < accum < 1.5 s, etc. I could increase the timer Preset as much as I need.

Just wondering if there is another way to do it? Will my method work?

Thanks in advance!

Just create a FIFO buffer where the first index is sent every 0.5 seconds if it contains data. Shift the data on every transmission.

Taking from CommissioningMan's advice, I'd put all the commands you'll ever use in an array of strings.

Your FIFO buffer would just be an array of INT's with the index of the command to send. This does assume that the command doesn't have something that changes like a setpoint, for example... but even then you can create exception logic for it.