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Messages - BLF_Electronics

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1
Technical support / Re:PID question
« on: November 07, 2005, 05:11:32 PM »
Thank you for the quick response. The new compiler fixed the problem.

2
Technical support / PID question
« on: November 04, 2005, 09:00:08 AM »
I need to use 10 channels of the PID. I used the PIDdef to define all ten channels. When I attempt to run the code and it gets to the following line I get an error message with the 9 highlighted. Has anyone attempted to use this many PID channels? The manual states 16 channels are available. The first eight work fine. Any comments will be appreciated.

DM[D+6] = PIDcompute(9,DM[D+5])

Error: Unknown Keyword


3
Technical support / Re:Interesting projects
« on: July 21, 2004, 09:44:30 AM »
I am always interested in hearing about projects that other people are working on. I recently used the T100MD controller for a project that used a laser to read material thickness. The laser was mounted to a stationary table that had a stepper controlled slide that the material was clamped to. The entire system was tied to a computer with an HMI written with visual basic that downloaded the test and stepper motor parameters via a custom written driver via the rs232 port to the T100MD. The speed of the table was controlled by the T100MD via the stepper motor. The material thickness was also displayed on the HMI and material setup parameters were saved to a database file for easy reuse. The T100MD is an amazing controller for the money and I will be looking for more projects to use it on.

Brian Ferry

4
Technical support / Re:Visual Basic Code
« on: July 09, 2004, 12:15:08 PM »
I have created a code module that allows reading and writing to the Tri-plc using host commands for a project I recently worked on. If anyone would like a copy of the code to use in your own VB projects send me an email at bferry@blftech.com and I will send you the code. I am also writing an HMI package in VB to use with the Modbus drivers to communicate to the Tri-plc's as well. This still needs some work but is looking very promising.

Thanks,

Brian Ferry

5
Technical support / Re:Reading counter present value
« on: February 13, 2004, 02:51:09 PM »
The logic you have listed will work in a [CusFn] as it is scanned continuously. If you use it in a [dCusF] it will only work if the rung goes true when the counter = 1. Try it with the [CusFn] and see if it works for you.

Brian Ferry
BLF Electronics

6
General Discussions / Re: Programmable weighing & batching controller
« on: April 15, 2003, 04:09:13 PM »
I have designed and built several batching systems with various types of hardware. If you use a scale indicator that has the electronics for the load cell excitation voltage you can usual interface the indicator using analog out or RS232. Another option is using an itelligent module that provides the excitation voltage and a analog output but no display. Several companies offer these items and they are fairly easy to interface with. If you need more details let me know and I will try to help you out.

7
Technical support / Re: HVAC Control
« on: July 27, 2003, 07:18:29 PM »
You have a couple of problems here. An ENDIF statement needs to be at the end of the logic. You need to add the OUT1 to the output labels and the T < 1.5 is not a complete statement. It needs changed or removed depending on what you need to do with it. I ran it like this with no syntax error. Hope this helps you.

IF (S-T) > 15
    SETIO OUT1
ELSE
    CLRIO OUT1
REM  T < 1.5
ENDIF

8
Technical support / Re: Stepper Motor control question
« on: December 17, 2003, 08:56:55 AM »
I appreciate your response and ideas. I checked my interface circuitry and it is solid. I have some current limiting resistors installed and they work fine. I found by increasing the acc value to 600 for the stepspeed command that the stepper smooths out and works well. I have a limited number of other functions running on the plc and I can go up to 14000 pulses with no loss in system performance. This should now work well for my application.  

Thanks,
Brian Ferry

9
Technical support / Stepper Motor control question
« on: December 16, 2003, 07:26:18 AM »
I have a question using the Stepper control with the T100MD+ PLC. I am using the stepspeed command in a dCust function to setup the initial move parameters with the default values I am storing them in the DM variables as follows.

DM[1] = 5000 'Pulses Per Second
DM[2] = 100   'Steps to reach full speed
DM[3] = 500   'Default Forward pulses per move
DM[4] = -500  'Default Reverse pulses per move
DM[5] = 2     'Default Delay time between moves
DM[6] = 20     'Default number of moves

stepspeed 1,DM[1],DM[2]

I then issue a stepmove command in another dCust function based on logic that looks at the time delay between moves after the step complete relay becomes true.

stepmove 1,DM[3],10

Everything works fine until I set the pulses per second up to 5000. At that point I get some oscillation in the stepper motor and it may stall. I am using a SilverPak integrated step motor and driver from Lin Engineering that is good up to 20Khz as the max step frequency. The specs also say the minimum step low time is 20 microseconds which should not be a problem at the 5000 pps setting. Am I doing anything that appears incorrect and do you have any ideas? I have also moved the motor only one move at the 5000 pps and get the same results. Everything works fine at a slower pps.

Thanks,

Brian Ferry

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