PVED-CC float position

[Rafal_Typiak]

Hi,
I have a PVG32 with PVED-CC coils, some of which have a floating position. However I'm having a hard time in making them reach the float position. I'm using a simple Tx block to send control data, where the address is the coil's ID, 1st byte is the spool position value and 3rd byte is the direction (1 or 2 for moving forward and backwards). The thing is that as the floating position is actually achieved at the cost of maximum spool's position in one direction I was told to simply force the spool into this position (say BYTE1:250 and BYTE3:1) and it should do the trick. But it doesn’t. I've read through the manual and it says that there is a special position for float. It's value is 3. But It's not responding if I sent 3 through BYTE3. I've tried using CANKing to get the response from the coil when I move it manually. I can see that the spool is physically capable of reaching the float position. I get the values and direction at which this is achieved but when I send those data I get nothing. I've always been using this method of steering the PVED-CC and it worked well so far. But it fails now. Could someone help me out? I'd appreciate any suggestions. Maybe there's a special block for PVED-CC coils? I'll take a look at the SD download page.

Cheers,
Rafa?

[Neil]

Hi Rafa.

Have you mechanically checked the spool moves the full 7mm, ie spool adjusters are not restricting movement?

regards Neil.

[Neil]

Also try byte 2,3?

KR Neil

[Rafal_Typiak]

Yup,
I've already done that. I've checked to see if the spool is physically capable of achieving the float position (the hydraulic actuator is getting 'numb' when in float), and I've tried sending different data on Byte 3. As the datasheet sais, Byte 2 is reserved. I don't know for what but I got the impression that it should have a '0' value. And so this leaves me with Byte 2 as the 'valve state' data. I'm sending 1 or 2 (decimal) to retract or extend the spool. But sending 3 basically does nothing. How do I know? Well each movement of the spool is being represented by a green LED. Each time the coil is in warning or energy saving mode (basically does nothing) it goes to an orange LED. Well..... when I send '3' (still decimal) the LED does not change from orange. I've tried sending Byte1: 0 Byte 3:3, and Byte1:250 Byte 3:3. None of which does anything. I'm totally at a loss here. Don't know what to do especially as I can mechanically move the spool to the float position.

I'd really, really use some help. I'm nearing a deadline when I should get this bloody spool to move where I want it to, but It's still ignoring me

Rafa?

[Neil]

Rafa,

the litrature states byte 1-8 in, real terms it should be byte 0 to 7 (8bytes)
Therefore byte 3 is actually byte 2 in the CAN world and byte 1 is reserved.

NR

[Rafal_Typiak]

Yup again,
I know that. I said I was sending data on bytes 1 and 3 because I meant 1st and 3rd byte. In reality I was sending it to 0 and 2. Just saying that I'm sending it to a 0 byte sounds strange

pic below:

[mebib]

Hi Rafa

In my application, the float is working by sending a "0" on Byte0 and a "3" on Byte2, as long as the Spool-Data and the OEM-Data inside the PVED are set correct. By default, the float will not be available.
There are a few settings, you should check inside the PVED, especial the following:
-Spool type
-Float port
-Float Threshold

Regards

[Rafal_Typiak]

oh.... great. than I'm screwed. I don't have WebGPI. I never needed it and the time (not to mention money) needed to order and buy it in my company will exceed the time I have to finish the vehicle. Crap.
Thanks anyway.

[mebib]

Hi Rafa
How do you set the node-ID's? You don't essential ned the WebGPI to change the settings in the PVED. You can do this by sending of a bunch of CAN-messages, but it is a quite big job to do it.

With your explanation, it seems to me, that your PVED is already set up for the float spool. Do you know about the function of the Float Threshold? If this setting is not 0, you have to move the spool in the direction of the float position, bevore you can switch to float. So you can not switch the valve to float position out of neutral or energy saving mode.

If this is not working, you really ned to know, what your settings in the PVED are.

Keep trying...

[Rafal_Typiak]

As far as setting node ID goes ... I don't set them. I order coils for specific projects and I ask SD to ID them and they do. As for changing if something goes wrong I ask one of the Polish SD representatives who has WebGPI and he visits us. The problem here is that the vehicle is somewhat 400 km away from our company and I only have a limited access to it (I'm not really happy about that but hey, that's how it goes sometimes) so I can ask him to drive around the country with me just so I could use his hardware/software.
I have found one coil which has a spool with a float position and connected it to a PVG32 which I have on the spot. Just for testing. Strange thing is that I was able to reach the float position but without sending 3 on 3rd byte. All it needed was a maximum position on one direction (250 and 1). And it worked. Could it be that the coil itself has an old software and the spool simply has the float position? Because the response from that coil was that the coil is NOT in float (it didn't return a 3). It was still in the retract position (1). Well... when I'll be given the time at the vehicle, I'll have to try that "sending of a bunch of CAN-messages". It'll be tricky but hell. No pain no gain, right?

[mebib]

By default the 7mm spool travel is linear scaled to the 0 to 250 of the command. The float spool will reach the max flow at 4.8mm.

So the quick (and dirty )way to do it, is when you use the default settings of the PVED and send about 172 for max flow in both directions and 250 for float position.