Remote Access on Cisco Devices Console Port

[santipongv]

I have similar problem on my current US Robotics Modem used for remote access to console port on Cisco Device at several locations. The dip switch settings are correct and yet I can intermittently connect to the remote devices. I tried Zoom modem but am unable to configure it to work with console port. Are there other modems I can use?

[#2]

I think the type of device is a Remote Management Switch (RMS); the RMS allows a PC to control power and serial channel access to up to 4 devices. The specific product is sold by Black Box (SW555A). The RMS has one Master Port (DTE) and four "Device Ports" (all DCE). The Master and Device ports are all DB-25s and all ports use hardware flow control.