YORK MCC and LDC-34 interface

[digo]

I've got a York Codepak chiller with an MCC (microcomputer control center, documentation # 160.65-PA2.1 ) that was originally tied to an LDC-34 ISN controller as its remote display interface (circa 1993). The operators have been running this plant in manual since day 1. I don't believe this interface has ever worked, as the MCC has an RS-422 interface and the LDC-34 has an RS-485 interface.

Our responsibility on this job is to reset the CHWS setpoint via an input on the LDC-34. The ISN takes the signal, and the desired result shows up on the lcd screen, but it doesn't make its way to the MCC.
I have a hunch that a simple RS485<->RS422 converter would take care of this problem...
I have a feeling they engineered the system having the LDC-34 interface with a different panel than what was supplied with the chiller.

Our customer does not wish to bring JCI/York into the mix (I don't blame them).

Has anyone dealt with such beasts before?
I'm thinking one of these could solve the issue: http://www.rs485.com/prsfc44t.html

Any comments appreciated.

Thanks,
Digo

[former frontliner]

the ldc 34 can talk directly to the chiller rs 485. the chiller micro has a rs485 port and needs to be configuried and addressed. the ldc also needs to be configured to talk to the chiller and if it supposedly never worked there is little chance you will be able to make it work without the documentation.

[digo]

the ldc 34 can talk directly to the chiller rs 485. the chiller micro has a rs485 port and needs to be configuried and addressed. the ldc also needs to be configured to talk to the chiller and if it supposedly never worked there is little chance you will be able to make it work without the documentation.

configured and addressed via a special tool, or will I be able to hack away at it from hyper terminal? I heard this MCC follows the "de facto" VT100 terminal emulation standard.