Background
All modern Davis stations (Vue and both cabled and wireless VP2) use the same basic protocol for transmitting data from sensor transmitters to console receivers.This protocol uses a set of eight data channels, which are actually time-based rather than frequency-based, to allow the consoles to receive data from a maximum of eight different sensor transmitters (although the Vue and cabled VP2 consoles can only receive from the ISS transmitter plus, optionally, for the Vue only, an anemometer transmitter channel).
The console must be configured to receive data on the same channel and from the same transmitter type as the transmitter is actually set to. If console and transmitter are not correctly paired then data from that transmitter will not be decoded and it will appear that readings from that particular transmitter are missing. In addition to correct pairing of transmitter and console channels, there are four other important rules:
- Any channel that is not actively in use by a particular transmitter must be set to OFF at the console. Failure to observe this rule can result in loss of readings from an otherwise correctly-configured transmitter because the console may be looking for the same data on two competing channels;
- The correct transmitter type must be set at the console, in addition to the correct transmitter channel;
- If data from a particular transmitter is being received via a repeater then the console must be correctly configured to receive that particular channel from a repeater rather than direct from the sensor transmitter;
- The general rules as to which combinations of transmitter type can be received by which console type must be observed at all times. Thus a cabled VP2 can only receive data from a single ISS transmitter and only on channel #1; a Vue console can only receive data from one single ISS plus, optionally, one anemometer transmitter; no console, other than an Envoy8X unit, can receive data from more than one ISS or anemometer; etc;
In general, setting up all standard Davis weather stations should be very straightforward. All stations are factory-configured to operate on channel #1 out of the box (indeed the cabled VP2 console can only operate on #1) and should simply work immediately. However, if you wish to switch a Vue or wireless VP2 to use a different channel or have a more complex multi-transmitter set-up with a wireless VP2 then it is clearly important to configure the channel settings correctly at the console.
And for any issue involving an otherwise unexplained loss of readings from a particular transmitter, it is always worth double-checking the channel settings. The setting can have become mis-configured as a result, for example, of some inadvertent button-presses at the console or, rarely, because of some external event, eg a mains spike. Correcting the configuration will typically solve the problem.
Setting and checking the data channels
There are actually two approaches to setting/checking the data channels – either directly on the display console or via the Weatherlink software. With an Envoy console, software is the only option of course. Third-party software will often not provide access to the relevant settings – the Davis Weatherlink software is the more reliable tool to use.
It is actually relatively simple to set the data channels on the display console, but it’s a topic that users occasionally struggle with. Instructions are provided in detail in the console manuals (see the section ‘Screen 2: Configuring Transmitter IDs — Wireless Only’ in the Setup section on p10 of the current VP2 manual and the corresponding section ‘Screen 6: Configuring Transmitter IDs’ on p9 of the Vue manual). It is worth finding and reading through this short topic in detail – the instructions are clearly set down but must be read carefully.
If you have a Weatherlink data logger and are running the Weatherlink software then you can control all of the console channel settings from the ‘Set Transceiver’ menu option on the Setup menu of Weatherlink. This dialogue should be fairly self-explanatory and there is the Help within Weatherlink if needed.
The comments below cover checking channel settings via the display console:
Checking the transmitter channel(s)
First, be sure that you know which channel each of your transmitters is operating on. On a cabled VP2 station the only option is #1. And with a new Vue or wireless VP2 station then #1 should be the default setting. This can be checked for the Vue by counting the number of LED flashes after a press on the ISS pushbutton (see p6 of the Vue ISS manual) or on the wireless VP2 by observing the DIP switch positions on the ISS transmitter board. Switch positions are described on p12 of the VP2 ISS manual, but note that of the 4 DIP switches only positions 1-3 control the channel setting. DIP switch 4 is a test switch for troubleshooting possible transmitter faults.
If you are experiencing reception problems then it’s always worth double-checking that the expected channel settings are correct. On a wireless VP2 ISS, you can try flicking an individual DIP switch back and forth just in case a particle of eg grit is preventing full contact, but obviously the DIP switch must be returned to its correct position.
Checking the display console channel(s)
These are some brief summary instructions. Consult the console manual for more details. Changing and checking the channel settings is easier than some new users imagine but does need to be done with a little care and logical thought. Also, do not make any changes to the settings unless you really mean to do so – the initial review is simply to check what the channel settings currently are.
- Enter setup mode on the console (Vue: 2nd then Setup keys; VP2: Done+Cursor – keys together);
- Move to the ‘Configuring Transmitter IDs’ screen: Look for the ‘Receiving From’ message on the screen – press and release the Done button until you see this message. Then press the Done button one more time.
- What you’ll see now differs a little between Vue and VP2 consoles. A Vue will say ‘STA 1’ followed by a name such as ‘Vue ISS’ or possibly ‘OFF’. A VP2 will say simply ON (or OFF) again followed by a name such as ‘ISS’ in brackets; above the message a small digit ‘1’ should be visible on the VP2. In both cases, the ‘1’ indicates that this is the channel #1 setting. An ‘OFF’ message denotes that the channel is not active. The name that follows the ON or STA 1 message is the station type that the channel is currently set to receive. For a simple system this will usually be just ‘ISS’ but there are a number of other options (WIND, TEMP, SOIL etc) depending on the station model.
- You can turn that channel ON (active) or OFF (inactive) by using the cursor +/- keys to toggle the setting. The message you see should change accordingly.
- You can change the transmitter type that the console should expect to receive on that channel by pressing the GRAPH key which should run through the sequence of types available on that console with each press of the key. A simple system should just be left as ‘ISS’.
- Repeaters: If your system uses one or more wireless repeaters then you will need to configure the channel accordingly by cycling through the repeater options with repeated presses of the Chill (2nd then WIND) button. Do not use this function unless needed. If you ever see the term ‘Repeater’ or ‘RPTR’ in a channel setting message when you’re not intending to use a repeater then this is a mis-configuration that needs correcting. Complex repeater configurations need very careful reading of the repeater instructions,
- Pressing the right-arrow cursor key will now take you to channel #2 (ie STA 2 on the Vue model) where all of the instructions above can now be used to configure that channel. And so on through the other channels #3 to #8 and back round again to channel #1. The left-arrow key can equally be used to move back through the channel sequence.
- All channels not required should be set to OFF. On a simple system with just the ISS as the only sensor transmitter then this will mean that all seven other channels should be set to OFF. In the case of reception issues it is always worth checking that all unused channels are actually OFF otherwise interference with reception on the main active channel(s) can result.
- When all channel settings have been successfully made and checked then Setup mode can be exited with a long press on the Done button. Leaving Setup mode causes the console to search afresh for the transmitter signals and it may take 2-3 minutes, occasionally even longer, before all readings are being updated on the display.
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