bluetooth /wireless instead rs232 cable

Hello Guys!
I have a problem with a wireless-bluetooth communication between a plc and a panel (if I use a rs232 cable the communication works very well) but with the bluetooth device the communication is slow and often is interrupted: it's impossible to obtain a stable communication (also trying to increase the settings on the panel about the idle time...).
The producer of these bluetooth devices is the Wireless Future (does anyone know it?). They say the maximum delay introduced by their products is 100ms maximum.
Does anyone know devices with less delay? And if is possible to find wireless devices based on a different technology (i.e.: different from bluetooth) that introduce a lower delay?

OK so I do a Google on "wireless future" and get like 7 million hits. So can you provide a link to the manufacturs website??

Thanks, Mike.

sorry...:
http://www.wirelessfutures.co.uk/

I use those without too much trouble, at 115KBaud.

A few things to check:

1 - Power Supply. Try using a very steady 5VDC supply to the module, and putting a .001uF and a 4.7uF capacitor right where your power feeds into the Bluetooth module.

Reason - These devices can have problems with noise coming in over the power lines, and also don't like power fluctuations.

2 - Assign a new PIN code for each pair you use. Put the PIN code on a lable, and affix it right to the boards (and on the outside of enclosures if you use them).

Reason - Although they only pair to 'First Available', the extra security of unique PIN codes makes sure they are never subject to erroneous capture of another device. (Other Wireless Cable Modules, PDA's, Laptops, Cell Phones, etc).

3 - They are still subject to interference from sources typically found in plants, especially PWM AC Drives. If that is the problem, you might try input/output reactors on nearby drives, and possibly shielded motor cables if possible.

**Note - I have had one pair that was damaged, it would initiate comms, and then drop the link on one of the modules TXD line, since then, I first burn them in with a longish (30 minute) hyper-terminal file transfer each way.