Regarding a means to locally controlling the camera via RS232, there are several options....
1. Buy the official THV PM series remote controller (sadly rare and expensive as Industry pays serious money for them)
2. Build a simple pre-programmed RS232 remote controller that sends the command strings in response to a button press. Arduino can easily do this task.
3. Buy a programmable RS232 keypad and program it with the RS232 command strings as key macros. Genovation made such keypads but they cost around £100.
4. Find a suitable Audio Visual remote control panel used to control AV equipment over RS232 links. These are expensive new, but available on eBay at reasonable prices
5. Use a laptop or tablet PC to control the camera via a program that can send RS232 command strings in response to button or mouse inputs. This has the disadvantage of boot time and bulk but the advantage of versatility.
I have the original AGEMA/FLIR remote controllers so do not have a great need for an alternative solution
I have bought a few Audio Visual equipment RS232 control panels from Extron, Procon and AMX. I have some 6 key, 8 key and 16 key types. Each controller has individually programmable keys and is designed to send a RS232 command string when the key is pressed. A software utility assists with the programming side of things, including data format and baud rate. Procon was bought by AMX so the control panels are the same. Care is needed to buy 'Master' controllers and not 'Slaves' and the controllers must include AV equipment control via RS232. Some are designed to control a video switch or operate on a network to a main controller. Those do not always offer direct RS232 output for equipment control as well. 'IR Blaster' LED output is common and of no concern as long as RS232 is also present.
I attach a picture of my favourite AMX control panel. I bought this particular one recently. It has 16 keys arranged in a useful layout for controlling a Thermovision camera
All key legends may be changed and are just acetate sheet. You can print new ones with a laser printer and laser compatible transparent sheet. The keys are all backlit with blue LED's. Lovely bits of kit and very versatile so I have bought a few over the years.The 16 key control panel supports multiple RS232 appliances via its three RS232 output ports. Expect to pay between £12 and £40 for such a unit on eBay.
Fraser