DF1 command to write a single bit to PLC5?

Hi,

I am using the Tuxeip library to talk to a customer's Allen-Bradley PLC5. Tuxeip currently uses DF1 command 0F 67 (Typed Write) to write binary values to the PLC. The only problem with this is that Typed Write can't change individual bits, only the entire word. I can get around this by reading the current word from the PLC and then re-writing it, but this is obviously problematic -- what if the value changes in the PLC in the meantime? It would be much better if there were a way to write a single bit without changing the rest of the word.

Can anyone suggest a better command to use when writing single bits to a PLC5? 0F 26 (Read-Modify-Write) seems to have the same problem, but what about 0F 02 (Bit Write)? Does anyone have any experience with that one?

Thanks for any help you can give me!

This works for the SLC and micrologix, so it may be the same for the PLC5:

http://www.iatips.com/pccc_tips.html#slc5_cmds

Those Protected Typed Logical Writes seem like a good idea, but the Rockwell DF1 manual says that PLC5s "can initiate these commands, but cannot respond to them". I'll probably use them for SLC support, but I'm still stuck for PLC5. Any other ideas?