Communication issues are among the most common problems people run into with their Pentair pool equipment. The following problems can be caused by faulty communication:
The good news is finding the cause of these problems isn't rocket science and involves no black magic.
The first thing you need to know is that Pentair systems use an RS-485 interface for serial communication between connected devices, operating at 9600 baud (8/N/1). If you're familiar with the RS-485 standard you can skip the next section, otherwise I'd recommend giving it a quick read to get the gist...
Step 1: Is everything connected?
This may sound obvious but the very first thing you want to check is whether your comm bus wires and connectors are making a good electrical connection.
Pentair systems have four terminals on the comm bus connectors... the middle two are data lines A and B (labeled yellow/green), and the remaining two are Power (red, ~15vdc), and Ground (black). The red/black wires are used to power any devices that are connected to the comm bus, such as transceiver cards, indoor controllers, spa remotes, screenlogic wireless and/or protocol adapters.
The 4-conductor wires that connect everything go bad more often than you'd think... animals chew them, shovels break them, sunlight decays them and sometimes lightning vaporizes them! The terminal blocks the wires screw into can also corrode, fouling the connections.
NOTE: Be aware that the outdoor board's comm port may have many cables connected to a single terminal block, or there could be a single cable that goes to a "port expander" or a salt cell surge board, to which more comm cables may be connected.
Give everything a good visual inspection. Check for nicks in the cable, chew marks, corrosion on exposed wire, degraded insulation (a lot of cable is not meant to be exposed to UV). I also take this opportunity to quickly inspect the boards for any damage, signs of corrosion, burned parts, etc.
TIP: If the wiring is suspect - and even if it's not - I will connect devices to the outdoor board using a short 2 foot "known-good" cable. If the device works with a short cable but not with the installed wiring... you've found the problem. If you've got a short cable - or it's easy for you to make one - I'd do this test before testing the cable!
- pressing a button on a remote or indoor controller does nothing
- an Intelliflo pump won't run the schedule
- screenlogic can't control the system
- communication timeout errors show on the intellitouch indoor panel
- an Easytouch wireless remote or indoor panel shows "No Comm"
The good news is finding the cause of these problems isn't rocket science and involves no black magic.
The first thing you need to know is that Pentair systems use an RS-485 interface for serial communication between connected devices, operating at 9600 baud (8/N/1). If you're familiar with the RS-485 standard you can skip the next section, otherwise I'd recommend giving it a quick read to get the gist...
RS-485 Basics
Unlike serial interfaces that have separate Transmit (TX) and Receive (RX) wires, RS-485 uses two "differential" data wires for sending and receiving data. These data wires are labeled "A" and "B" (or sometimes D+ and D-) and the polarity of each wire relative to the other determines whether the data bit is a 1 or a 0... i.e. if A<B the bit is a 1, and if A>B the bit is a 0. Other characteristics of RS-485 communication include:- All devices on the system are connected to a data "bus", which basically means that the "A" wires from all devices are connected together and the "B" wires from all devices are connected together.
- Only one device is supposed to "talk" on the bus at any given time but all devices can listen.
- If you looked at the RS-485 signal on an oscilloscope you'd see that the signal varies between approximately +12 and -7 DC volts.
- Each device uses a special driver chip to control whether the device is talking or listening and converts the RS-485 signal into something the micro-controller can use.
- The driver chip is easily damaged if the signal exceeds the maximum input ratings (typically +/- 12 volts on the A/B wires), and a bad driver can break the whole comm bus.
RS-485, <TLDR>:
From all the above RS-485 drivel you should take away the following 3 points...- Both the A and B data lines are required for any communication to work - it doesn't work with just one.
- Everything connects to a single data bus - I'll call it a "comm bus" - and one bad device can foul up communication for everybody else
- The driver chips are easily damaged
Troubleshooting
Before we dive into the troubleshooting steps, here are a couple of things to note:- If you have a spa with an is-10 "spa-side" remote (this has rows of buttons and a temperature display), check it first - they are notorious for failing and jamming the comm bus.
- Wireless remotes (Easytouch and Mobiletouch units) can be difficult to diagnose because the RS-485 link between the transceiver and the outdoor unit OR the radio link between the remote and the transceiver can be bad. A begged/borrowed/stolen "known good" remote or transceiver is handy for testing.
Step 1: Is everything connected?
This may sound obvious but the very first thing you want to check is whether your comm bus wires and connectors are making a good electrical connection.
Pentair systems have four terminals on the comm bus connectors... the middle two are data lines A and B (labeled yellow/green), and the remaining two are Power (red, ~15vdc), and Ground (black). The red/black wires are used to power any devices that are connected to the comm bus, such as transceiver cards, indoor controllers, spa remotes, screenlogic wireless and/or protocol adapters.
The 4-conductor wires that connect everything go bad more often than you'd think... animals chew them, shovels break them, sunlight decays them and sometimes lightning vaporizes them! The terminal blocks the wires screw into can also corrode, fouling the connections.
NOTE: Be aware that the outdoor board's comm port may have many cables connected to a single terminal block, or there could be a single cable that goes to a "port expander" or a salt cell surge board, to which more comm cables may be connected.
Give everything a good visual inspection. Check for nicks in the cable, chew marks, corrosion on exposed wire, degraded insulation (a lot of cable is not meant to be exposed to UV). I also take this opportunity to quickly inspect the boards for any damage, signs of corrosion, burned parts, etc.
TIP: If the wiring is suspect - and even if it's not - I will connect devices to the outdoor board using a short 2 foot "known-good" cable. If the device works with a short cable but not with the installed wiring... you've found the problem. If you've got a short cable - or it's easy for you to make one - I'd do this test before testing the cable!
Check Continuity
If the visual inspection checks out OK, shut off power to your pool equipment and use a multi-meter to test the conductivity of the comm wiring. This isn't hard, and Google is your friend if you've never done it.
TIP: Some people will also do what I think of as a "complete conductivity test" now - by unscrewing lots of wires from terminal blocks and testing them all - but I'm lazy and like to do the easy stuff first... I'll at most make sure there's good conductivity between each terminal screw and the wire that comes out of it. Then I move on to Step 2 (sometimes I have to circle back).
A "complete" conductivity test can be tedious if you have a lot of devices - which is why I often do other simple check first - but to test conductivity on a single long comm cable I disconnect the cable from the screw-terminals, temporarily connect two pairs of wires at one end, and test for continuity at the other. For example, at one end I'd connect yellow to green... and at the other end I'd test continuity from yellow to green. If there's no continuity then I know there's a problem with my yellow or green wire)
Check for a Short
You can test for shorts pretty easily as well. Power everything down, pull the connector off the comm port and - assuming all downstream devices are disconnected - test for continuity between all permutations of the wires (you can eliminate the duplicates), i.e. red to black, red to green, red to yellow... black to green, black to yellow... yellow to green. If you get any hits on continuity then you've found a short.
Step 2: Is there power on the comm port?
Take a look at the devices connected to comm port - if they turn on then the chances are good that you've got power on the comm port connector and you can go on to Step 3. If they don't turn on - or run sporadically - you need to investigate further...
As mentioned above, there should be about 15 volts DC across the Red and Black wires... so pull out your multimeter and make sure you get that. You'll of course need the power ON for this, and you'll need to be very careful not to short the power or ground pins or wires to either data wire! Again, the maximum input on the driver chips is often +/- 12 volts DC... so touching the Red wire to a data line can kill it.
Step 3: Check for a pulse
Most devices on the comm bus give some indication of whether data is present on the bus. You'll want to check the following for each piece of equipment you've got:
Step 4: Identify the Faulty Device
I use the process of elimination to isolate and identify a faulty device. I'll unplug everything and then re-connect each device one at a time to see if ANYTHING can talk to the outdoor board. If I find something that can connect, I connect other devices until the communication fails. The key thing to understand is that any device can interfere with another's ability to communicate. And always shut the power off before connecting/disconnecting anything to/from the comm port!
Here are a few tips to help troubleshoot wireless connections:
If the visual inspection checks out OK, shut off power to your pool equipment and use a multi-meter to test the conductivity of the comm wiring. This isn't hard, and Google is your friend if you've never done it.
TIP: Some people will also do what I think of as a "complete conductivity test" now - by unscrewing lots of wires from terminal blocks and testing them all - but I'm lazy and like to do the easy stuff first... I'll at most make sure there's good conductivity between each terminal screw and the wire that comes out of it. Then I move on to Step 2 (sometimes I have to circle back).
A "complete" conductivity test can be tedious if you have a lot of devices - which is why I often do other simple check first - but to test conductivity on a single long comm cable I disconnect the cable from the screw-terminals, temporarily connect two pairs of wires at one end, and test for continuity at the other. For example, at one end I'd connect yellow to green... and at the other end I'd test continuity from yellow to green. If there's no continuity then I know there's a problem with my yellow or green wire)
Check for a Short
You can test for shorts pretty easily as well. Power everything down, pull the connector off the comm port and - assuming all downstream devices are disconnected - test for continuity between all permutations of the wires (you can eliminate the duplicates), i.e. red to black, red to green, red to yellow... black to green, black to yellow... yellow to green. If you get any hits on continuity then you've found a short.
Step 2: Is there power on the comm port?
Take a look at the devices connected to comm port - if they turn on then the chances are good that you've got power on the comm port connector and you can go on to Step 3. If they don't turn on - or run sporadically - you need to investigate further...
As mentioned above, there should be about 15 volts DC across the Red and Black wires... so pull out your multimeter and make sure you get that. You'll of course need the power ON for this, and you'll need to be very careful not to short the power or ground pins or wires to either data wire! Again, the maximum input on the driver chips is often +/- 12 volts DC... so touching the Red wire to a data line can kill it.
Step 3: Check for a pulse
Most devices on the comm bus give some indication of whether data is present on the bus. You'll want to check the following for each piece of equipment you've got:
- Intelliflo pumps with an LCD display on the keypad will show "Display not active" if it is able to communicate with the outdoor controller.
- Upon power up, an Indoor controller will take 10-15 seconds to show the Time, and another 10-15 to show the air temperature if it can communicate with the outdoor controller. The LEDs for any active circuits will also be illuminated. On Intellitouch units, Pressing the Heat button initiates a communication with the outdoor panel to retrieve the heat settings.
- An Easytouch remote will show "Auto" in the top left if it connected, or "No-Comm" if it can't talk to the outdoor panel... as mentioned above, this can be a radio problem OR an RS-485 problem.
- A Mobiletouch (1 or 2) that cannot talk to the outdoor controller will not show the time or temperature (similarly to an Intellitouch indoor panel), and again, this can be a radio problem OR an RS-485 problem.
- Transceiver cards have a 485 Link LED that flashes when a packet of data is received or transmitted... it will flash every second or so, or when a button is pressed on a controller
- Screenlogic protocol adapters that use a wireless link have an rs485 activity LED on the transceiver cards that will flash, similar to the transceiver cards mentioned above. **Those that are "hard-wired" to the outdoor panel do not have any externally visible indication that the comm link is working
Step 4: Identify the Faulty Device
I use the process of elimination to isolate and identify a faulty device. I'll unplug everything and then re-connect each device one at a time to see if ANYTHING can talk to the outdoor board. If I find something that can connect, I connect other devices until the communication fails. The key thing to understand is that any device can interfere with another's ability to communicate. And always shut the power off before connecting/disconnecting anything to/from the comm port!
Wireless Gotchas
Wireless remotes and screenlogic wireless links add another dimension to troubleshooting communication problems - as mentioned above the problem can be the RS-485 connection to the various wireless components OR the wireless radio itself.Here are a few tips to help troubleshoot wireless connections:
- For a wireless remote, stand near the receiving unit while you're testing. If you're having a radio problem it could be a faulty radio for sure, but could also be an interference or range problem.
- Try re-setting the wireless address... Easytouch and Intellitouch wireless remotes need to "pair" with the outdoor board. Consult the user guide to re-set this pairing.
- Remember to watch the RS-485 and Radio LEDs on transceiver cards... if the RS-485 LED never flashes, it's not talking to the outdoor board.
- An advanced move is to "sniff" the radio signal to see if the card is operating. The transceiver cards use the 915mHz ISM band... you can scan this with a software radio (SDR).
- older cards use a Linx chipset and will transmit around 916mHz (you can look up the specs on the fcc website using the FCC:ID on the back of the remote)
- newer cards use a Laird chipset and will transmit from 905-920mHz or so, and these utilize frequency hopping spread spectrum technology, so they are much harder to "sniff"
- a transceiver card connected to an Easytouch system will transmit a packet every second or so if it is working properly
- an Easytouch handheld remote will transmit a packet if you select an aux circuit or any of a handful of menu functions... you can use "Heat" from the menu, or any of the "air", "water", "solar" temperatures from the Diagnostic menu.
Great article. I’ve had to replace my Compool-to-EasyTouch upgrade board following storms twice in the last 5 months. Rebooting and resetting the EEPROM to factory defaults didn’t work. Comm is sporadic, so I’m guessing the RS-485 driver chip is damaged. Can this be replaced or are there any repair options?
ReplyDeleteI may replace the transformer board this next go around. Something has gotten very susceptible to power issues…
Thank you... if your comms are sporadic it's more likely to be the wiring than the rs-485 driver. When these chips fail it's usually because the internal driver, receiver, or both have burned up - so they don't work at all. I've never seen a chip fail such that "it doesn't work now, but will work later".
DeleteYou may want to look into surge arrestors, not just for your load panel, but also for any rs485 wires you've got outside. Swing over to the trouble free pool forum for some more recommendations.
If you still have the old boards, they can likely be repaired so you can keep them as spares.
Delete