I found in AVW200 manual page 5, says, 'Figure 1.4-2 and 1.4-3 indicate the number of interfaces that can be connected to one datalogger when using wireless interfaces or the SDI-12.' protocol'. And in Figure 1.4-2, four avw 206 are shown.
Does that mean the maximum number of avw200/206 that can be connected to one datalogger is only four? If yes, anyway to expand datalogger's capacity to accommodate more?
Thanks
If you using the SDI-12 scheme the limitation is the SDI-12 addressing (~25) x the number of available SDI-12 ports on the logger. SDI-12 signal cable length is also a factor. However, we would not recommend using SDI-12 usually as it is so slow.
If using radios, the address limitation is the number of available Pakbus addresses which ranges up to ~4000. In practise though the bandwidth of radio transmissions,number o repeating steps, house keeping beacons, possible retries etc becomes the limiting factor. Working out the exact limit is rather complicated as it depends on the measurement interval of the sensors and the topography, but with the normal slow measurement interval of VW sensors,
A first step to seeing what is possible and what settings to use would be to use the Network Planner tool that is incorporated in Loggernet.
Thanks for your reply. About the limitation for radio connection, that is what I am thinking. However, I think what shows in RF manual might be a little bit vague, especially for new CSI users.
The wording of the manual together with the diagrams referenced seem to indicate "four" as the limit for the number of AVW206/211/216 devices able to connect to a datalogger via RF401/411/416 radio, but that is incorrect. You can have many,many, more than that (as aps has indicated). The limitation comes in when you have multiplexers connected to the AVW2xx devices.
It is also true that you can have more than four SDI-12
based AVW200 devices connected to a datalogger. Once again, you get limited by the use of multiplexers on those devices.
We have initiated a change to the manual to clarify this.
Thanks for all your clarification.
just for clarification, the concept that many avw2xx devices can be connected via pakbus is not limited to just radio. for example using 4 sc105's, the two com ports, and the rs232 port, one could connect 7 to a cr800. or one could connect 31 avw200s to a logger over a single md485 network. and because of the nature of pakbus these can be mixed and matched.
just for clarification, the concept that many avw2xx devices can be connected via pakbus is not limited to just radio. for example using 4 sc105's, the two com ports, and the rs232 port, one could connect 7 to a cr800. or one could connect 31 avw200s to a logger over a single md485 network. and because of the nature of pakbus these can be mixed and matched.