How long does it take to write a program to a Scadapack through RS-232?

Hi guys,

I've taken on a new client, rural water district. They have an ancient system, with Scadapacks and NI Lookout. Some of their Scadapacks have been acting weird, so they went to eBay and bought some identical models of similar vintage (looks like late 90s, there are only RS-232 Dsubs, no USB, no LAN, etc). They've asked me to program these spares so they can swap them in when they have intermittent issues.

I have both of their eBay spares on my bench. If I try to monitor, it'll tell me that my program and what's loaded don't match but when I try reading to/writing from both none of them seem to want to do anything. I've let both sit for ten solid minutes, and my Rx and Tx lights are blinking but no progress seems to be made.

I've never programmed a Scadapack from a dsub connection so I'm wondering if it just takes forever, or are both of these units bricked?

UPDATE: Realized my station ID for Modbus was off. I was able to figure out what it was by using a Modbus polling program, and just changing the station until my commands didn't time out. Long story short, writing/reading through a dsub RS-232 definitely takes longer than USB or TCP, but it shouldn't take more than tens of seconds.

On a side note, SCADAPack's are not exactly large.

What model's are they. I would have thought for such small devices, rather than looking for direct old back-ups, the modern equivalent would be much better solution and switch out.