Messages

111

General Mach Discussion / Re: Unstable analog inputs

« on: February 03, 2012, 07:19:49 AM »

Thanks Ian,

I've never worked with modular arithmetic but it will give this old man something to do today. LOL. I guess I'll start here: http://www.math.rutgers.edu/~erowland/modulararithmetic.html.

Tony

112

General Mach Discussion / Re: Unstable analog inputs

« on: February 02, 2012, 04:39:58 PM »

Thank you, I'll play with that a little. I like it.

Tony

113

General Mach Discussion / Re: Unstable analog inputs

« on: February 02, 2012, 02:07:14 PM »

Yeah but if Y = analog input then it is always an integer, Right?

Then (Y/Z)*Z = Y = INT(Y/Z)*Z

Only when Y is not an integer will (Y/Z)*Z  not = INT(Y/Z)*Z

Just gives me something else to think about.
Thanks,
Tony

114

General Mach Discussion / Re: Unstable analog inputs

« on: February 02, 2012, 10:49:46 AM »

Thanks Ian,

One problem is, as I see it, with distinctive bands is that if the set point is near the edge of the band the output will be hunting between the two bands.
With “If b < (GetVar(609)-2.5) Or b > (GetVar(609)+2.5) Then
SetVar(609,b)” I was trying to get a fixed width band with variable location. This keeps sampling and keeping the output in the center of the band. I realize the “2.5” doesn’t do much good with the integers. Oops.

I probably misunderstood your formula. Relating to mine would it be:
b  =  INT (a/6.8267)* ?? EDIT: now that I look at it again doesn't (Y/Z)*Z = Y?

What I’m trying to avoid is the feed rate hunting while machining in FRO

I do like your way of thinking.

Tony

115

General Mach Discussion / Re: Unstable analog inputs

« on: February 02, 2012, 08:28:14 AM »

Hi Peter,

I was concerned that during a machining operation Mach might not keep up with calculating the vector velocity components of a multi axis feed twenty times a second.

Here’s the code I used in a macropump to buffer it a little. It is pretty jittery so I had to use wide deadbands.

Sub FRO()

a = getinput(64)
b= Fix(a/6.8267)   ‘150%
If b < (GetVar(607)-2.5) Or b > (GetVar(607)+2.5) Then
SetVar(607,b)
If GetVar(607) < 103 And GetVar(607) > 98 Then
SetDro(21,100)
DoOemButton(1014) 'reset overide
Exit Sub
End If
SetDro(21,GetVar(607))
End If
End Sub

Thanks for all your help.

Tony

116

General Mach Discussion / Re: Unstable analog inputs

« on: January 31, 2012, 04:41:36 PM »

Will the floating feed rate overwork Mach while running a program?

Thanks,
Tony

117

General Mach Discussion / Re: Unstable analog inputs

« on: January 31, 2012, 04:36:09 PM »

Thanks Peter,

I'm using the +5V from the ModIo. Could I use an external power supply say from the PC and have less ripply? How about a good stand alone power supply?

Thanks,

Tony

118

General Mach Discussion / Unstable analog inputs

« on: January 31, 2012, 04:03:39 PM »

I’m using two 10K pots for analog inputs through a ModIO for FRO and Speed % DROs The DROs float around about + and – 2% from set point. Is there a way to buffer or smooth out the inputs. I could write a macro with 100 “deadspots” but that doesn’t seem to be the way to go. Any help would be appreciated.

Thanks,

Tony

119

Modbus / Re: How to change output settings?

« on: January 28, 2012, 09:28:09 AM »

"Writing FF to register 103 should turn off the flashing to all outputs.

The Alternative way is to use the Modbus Config tab, acessed from the Modbus Config page.

Cheers,

Peter."

Hi Peter,

Do I uncheck the "Limit Err Flash" checkbox and do I need to jemp the Boot terminals to write to the Modio?

Thanks,
Tony

120

Modbus / Pulsating outputs

« on: January 27, 2012, 11:50:58 AM »

I’m just setting up and testing a new ModIO V6.3 board per instructions in user guide ModIO_User092.PDF and find one unusual condition. Following the instructions on page 10, Lighting an LED, activating output 3 on port 0, pin 6 all goes as expected. DOut 4 through 7 all respond to the active low, high state by either staying on or off. However, DOut 0 through 3 flash on and off at about 5 / second with the same setup.

I have a pot set up on analog 1 for test that is read and shown with the VB Script Editor with:
 A= Getinput(64)
Print A

I have nothing wired to analog 2 and 3 but when reading them with A=GetInput(65 or 66) they seem to be reading (64). With none of the analogs wired I get a reading of about half (500+-).

This is from the LCD
ModIOtm   SN:0346
H/W:       F   S/W:022F
Id:      6  57600,8,1,N
DAL1H2HpfkGEd – DEF –

Any thoughts would be appreciated.

Tony