Erratic PM3

[John Hendrie]

This morning I noted erratic behavior in my PM3 monitor. I was rowing a long piece at approximately 2:20 - 2:25 pace when the pace suddenly dropped near 2:00 and bounced around between 1:50 to 2:10 on each stroke. I know I was not rowing anywhere near that pace. I quit that session and started a new one and saw paces as high as 4:00+.

I know the elapsed time was correct as it agreed with my Suunto stop watch/HRM which makes me question the distance counter. Any suggestions?

Thank you

John Hendrie

[Citroen]

How old is it?
What model of rower is it on?
What level of PM3 firmware?

[Carl Watts]

Sounds like it has jumped from model D/E to model C in the settings.

Check in the product ID that it is set for the right Erg.

The older 2003 2004 models can suffer from PCB corrosion in the tach amplifier area and give erratic or eventually no reading but it is more likley just a setting.

[John Hendrie]

How old is it?

It was delivered in November 2007 as a replacement for a defective PM3.

What model of rower is it on?

It is on a Model C

What level of PM3 firmware?

When received it was at v97 but I think it has been upgraded. How do I determine the current level?

Thank you

[John Hendrie]

Sounds like it has jumped from model D/E to model C in the settings.

Check in the product ID that it is set for the right Erg.

I doubt that because the avg/500 meters is all over the place but I will check that it is set properly. How do I do that?

The older 2003 2004 models can suffer from PCB corrosion in the tach amplifier area and give erratic or eventually no reading but it is more likley just a setting.

Thank you

[jvincent]

When received it was at v97 but I think it has been upgraded. How do I determine the current level?

Thank you

From the Main Menu -> More Options -> Utilities -> Product ID

[John Hendrie]

How old is it?

It was delivered in November 2007 as a replacement for a defective PM3.

What model of rower is it on?

It is on a Model C

What level of PM3 firmware?

When received it was at v97 but I think it has been upgraded. How do I determine the current level?

Checked it out and it is v 105

Thank you

[John Hendrie]

More info in response to the post by Carl Watts. I checked the PM3 and it is configured for Model B/C. Also, my unit has a date code 1512006 (January 2006?) well after the 2003 2004 problem dates mentioned in your post.

This is a wild guess but I just started using a Suunto HRM. Is it remotely possible that the signal from that is messing things up??? I will try rowing without it tomorrow morning.

Thank you

[Citroen]

PM3 on model Cs can get the odd erratic reading for one stroke then it goes back to running normally - I see it occasionally on one of the six model Cs in my gym. It's a bug in the firmware. I've never been able to come up with a way to recreate it at will so I've been unable to discuss it with Scott H @ Concept2. If you can describe the problem in details then you should report it to C2.

It is 100% nothing to do with Suunto. Your PM3 doesn't even know that you're wearing a Suunto HR strap. Only the PM4 can see that.

[John Hendrie]

PM3 on model Cs can get the odd erratic reading for one stroke then it goes back to running normally - I see it occasionally on one of the six model Cs in my gym. It's a bug in the firmware. I've never been able to come up with a way to recreate it at will so I've been unable to discuss it with Scott H @ Concept2. If you can describe the problem in details then you should report it to C2.

It is 100% nothing to do with Suunto. Your PM3 doesn't even know that you're wearing a Suunto HR strap. Only the PM4 can see that.

I feel like a dunce. I usually wake my PM3 by pulling the handle from the cradle but this morning there was no response when I did that. I then turned it on by pressing Change Units, set "Just Row" and started - no response from the PM3. I then had the bright idea to push in the connector and voila, everything is now back to normal. Apparently yesterday I had a tenuous connection and today none at all. Being a mechanical engineer I should have tried that at the outset.

Thank you for your help

John Hendrie

[jvincent]

I then had the bright idea to push in the connector and voila, everything is now back to normal. Apparently yesterday I had a tenuous connection and today none at all. Being a mechanical engineer I should have tried that at the outset.

Ah yes, rule #1 of all debugging. Is the cable plugged in?

[bepah]

PM3 on model Cs can get the odd erratic reading for one stroke then it goes back to running normally - I see it occasionally on one of the six model Cs in my gym. It's a bug in the firmware. I've never been able to come up with a way to recreate it at will so I've been unable to discuss it with Scott H @ Concept2. If you can describe the problem in details then you should report it to C2.

It is 100% nothing to do with Suunto. Your PM3 doesn't even know that you're wearing a Suunto HR strap. Only the PM4 can see that.

I have that 'problem' as well. Erging @ 2:16 then for 1 stroke, I'm at 1:58.......for 1 stroke....I can up my effort but it takes me a couple of pushes to make that kind of move......

This happens almost every session......I have no idea on how to capture the incident......

[georgie]

Citroen wrote:
PM3 on model Cs can get the odd erratic reading for one stroke then it goes back to running normally - I see it occasionally on one of the six model Cs in my gym. It's a bug in the firmware. I've never been able to come up with a way to recreate it at will so I've been unable to discuss it with Scott H @ Concept2. If you can describe the problem in details then you should report it to C2.

I have a similar problem with my pm4. During a steady row of say 2:15 pace, the display will go down to the low 2:00's for a stroke, and sometime will go down further on the next stroke (I've seen as low as 1:45). At the same time the stroke rate will shoot up to as high as 88. It also goes the other way, recording the odd stroke of 3:00/4:00 pace. This is an intermittent fault and therefore I never know when or if it will happen. It will always give me an IND V code, therefore I am assuming that it corrects itself. It is very disconcerting though! I have now switched back to my old pm3 which works fine.

[Citroen]

It's an intermittent timing bug in the PM3 / PM4 firmware. If the processor is busy it misses the magnet going past the tacho sensor so gets an erratic reading for one stroke. Because of the way the PM3 / PM4 do rounding and averaging it's not a major problem, it's just an annoying niggle.

You could write to ScottH at Concept2 if it really bothers you and if you can come up with a test case where the problem is reliably demonstrated.

[georgie]

It's an intermittent timing bug in the PM3 / PM4 firmware. If the processor is busy it misses the magnet going past the tacho sensor so gets an erratic reading for one stroke. Because of the way the PM3 / PM4 do rounding and averaging it's not a major problem, it's just an annoying niggle.

Thank you Dougie. I believe it's more than just an annoying niggle though. On one particular interval session of 500 meters, I saw the avg. drop by 0.5 secs, and I'm sure it gave me a faster end result. If what you say is true, then why is it only an issue with some pm4's, and not all of them? Could it be that I'm using it on a model C?

To obtain proof is going to be almost impossible!