Security is excellent. The bluetooth dongle in the laptop USB port will talk to anything. However, each bluetooth serial port is pre-programmed from the laptop serial port to be in discover mode. Each bluetooth serial port is programmed with a password. The bluetooth devices are then "discovered" and "pair locked" via the password to a com port number.
At the moment I have 5 of these things and each bluetooth serial port is pair locked via password and serial number to comm 6, 7, 8, 9 and 10. Comm 5 is reserved for the bluetooth USB dongle. Each device has the comm port number clearly marked on it so I know which comm port number is in which PLC.
These devices will only run with comms settings of 8, 1, N and can be programmed to run at any baud rate up to 230 kbaud. These comms settings are fine for Omron as their "Toolbus" protocol runs 8, 1, N @ 115kbaud maximum speed.
The other requirement is that there has to be power available on, I think, pin 9 of the serial port you plug into. This suits me as Omron have this available. Otherwise a separate 5VDC power supply is required to plug into the bluetooth serial port to drive it. I have that available also for SOME of the older Omron PLCs that do not have 5VDC on pin 9.
When programming the device, for example, on your laptop, the 5VDC is obtained from a lead that plugs into the laptop USB port to power the device.
I guess these devices will not be suitable for everyone and all PLCs but boy I am glad they suit Omron!
The main network I run peer to peer is Omron Controller Link, it is token ring based. I use it for programming, peer to peer comms and also for SCADA, mainly Citect. I believe Wonderware also have an Omron FINS driver available for use with this network and Omron FINS Gateway middle software. Ethernet also works with the same middle software and so does serial. This enables online access to the networked PLCs by the SCADA and the programming software at the same time with all devices online to both sets of software. Just put the programming software on one section of the screen and the SCADA on another, change the program and see an instant change in value on the SCADA screen.
With the bluetooth serial ports I can still access all PLCs on the network from my laptop with the SCADA still quite happily accessing all PLCs at the same time using the same network, whether it be Controller Link or Ethernet, from a different interface point.
Hope this helps but do not know if these devices will work happily with either AB or Siemens due to the 5VDC supply reqirement or the comms settings that the devices can handle.
Siemens seems to be a bit cranky and slow with respect to comms, particularly serial. The last time I used one on MPI it was pathetically slow and would only run @ 38.5kbaud max. We switched it to Ethernet to get some speed but comms performance was still much slower than I am accustomed to with Ethernet, in fact not a lot quicker than my normal serial interface when one considers the Ethernet was running @ 100 megs.
Have not tried AB for some time and certainly not Control Logix. I hear comms to these are pretty quick and one day may get to try one.
Despite my dislike for Ethernet, I sometimes have to use it. Usually to a SCADA system. I usually just use 1 Ethernet card in 1 PLC and run Controller Link as my peer to peer network. Everything is placed on the network and can be picked up in any PLC with the same address number as exists in the originating PLC. Makes it easy to then program the SCADA to pick up from the Ethernet port in the "access" PLC.