Joe Tauser

A quick Google search on "Modbus Power Monitor" yields several instruments that would do the job. You're not going to get transient capture, but if all you want to do is look at energy usage and phase data one of these would work fine. Joe T.

Is your display object set up as a numeric variable or a string variable? If you're loading it to an ML the display object needs to be a properly sized numeric. Joe T.

You have to connect I and V together because the I input is just a precision resistor to the 0V terminal. You still use the V input to read the voltage across it. Since the module knows the value of the resistor, it can translate the value of the input current from the voltage. This is the way all analog inputs work on all products. An A/D converter is nothing more than a voltmeter. Joe T.

Bob, Very nice ride- I am a fan of '60's muscle cars. If you can't calibrate the touchscreen after a couple of tries there is something wrong with the unit. Joe T.

I think your best best here is a small state machine instead of a bit-banger with all the timers tied together. I have attached a program that demonstrates this. You'll have to flush out the details. Joe T. Jazz stage example.U90

Bob, Is that a '67 Cutlass? Simon is exactly right about calibrating the touchscreen. If memory serves, Lantech uses a V290 monochrome unit. Enter Info mode by pressing the screen where there are no buttons for four seconds. If it asks for a password the default is 1111. You should be able to navigate the menus to get to touchscreen calibration. Joe T.

You can not access the SD card directly using data table functions. You could create logic to transfer data tables back and forth from the SD card and create a very large virtual data table. What exactly is your application? How many rows can you define with your current data schema? Joe T.

Unitronics uses a coil with a "T' address to represent a timer, the time is in clock format. You probably already know this. Here's how I link two timers to create a repeating pulse: Joe T.

OK, so my A.D.D. kicked in this afternoon and I was compelled to go to the German DIN standard homepage. The following picture greeted me at the top- These are the people who are deciding how we'll conform as industrial product developers. I'm thinking I definitely want the look of the fourth guy from the left when I go visit my customers in rural Missouri. Joe T.

Have you asked your friendly distributor for assistance? Read the Help on Math blocks and Compare blocks. The high-speed counter is mapped to an integer (I'd recommend an ML). After you do your math to get pulses per foot, run that result into a >= compare block and tie your stop output to that. Have an external start button wired to an input to start the process, and Store a 0 to the HSC register on a positive transition of when that's pressed. Take a swing at the logic and post your code. We can offer suggestions from there. Joe T.

I'm assuming you've got a PID run block in your program and you've verified that you have power to it. If it's in a subroutine, make sure you're calling the sub. Otherwise, look at the value of the status word of the PID block and then look in the Help at what the values mean to see if that will give some direction. Post your program so we can look at it if you're still having trouble. Joe T.

The PLC allocates memory based on what the user has defined in the application, and Trends are their own animal (not to be confused with user accessible memory such as MBs and MIs). You can't look at the actual Trend data, it's only accessible by the Trend object. In Visilogic, go to Build->Projected Memory Map to see what I'm talking about. You can also save Trend data to an SD card, but to view it you have to load it back. Joe T.

You're generating an AC signal. The way you get a stable DC signal from an AC signal is to add a filter capacitor and a load resistor. You'll have to play with the values until you get the DC level you want. Do a Google search on "sizing a filter capacitor" for some ideas on the calculations involved. Joe T.

RS 485 can be tricky, especially at high speeds. It sounds like you've got the wiring and the DIP switches set right or it wouldn't work at all. You most probably are getting reflections with your short cables. Unitronics recommend that you set the terminator at both ends, but I've found that it sometimes attenuates the signal too much. If you have access to a scope hook it up across the A & B lines and see what the waveform looks like and it's amplitude. You want to set your terminators so the peak-to-peak voltage is somewhere between 6 and 9 volts. Joe T.

Double-check the spec sheet on the -E4XB. You have to apply power to several places. Joe T.

In Unitronics RS 232 serial port land the connections are as follows: 2 & 5 are both ground 3 TX 4 RX So your cable would be Servo V570 1 2 2 4 4 3 Joe T.

I posted this a while back- PTO Example See if it answers your questions. Joe T.

For that kind of speed on that many channels you're going to have to buck up. I Googled this for a bit and this is about all I found: Acromag Ethernet Analog It updates all its channels in 10ms, for a measly $1700. You probably don't want to spend that much, but my experience is that high speed analog is not cheap. I've actually abandoned the PLC solution and gone to LabView with National Instruments PCI boards when I run into an application with these kind of demands. This was a hard-learned lesson, as the first time I ran into it I spent a over a month trying to make to make something work that was just not capable. Going that fast also makes the problem of noise much larger, but that's a story for another day... The remaining question is whether the PLC can get the data every scan over Ethernet using Modbus TCP. Just out of curiosity, what are you doing that requires such speed? Joe T.

Just how fast are you wanting to scan? Joe T.

What a pain in the butt.... I downloaded the Prolific v1.1 from the link on the forum (there's no mention of it on Prolific's website). Then I uninstalled the old driver and ran the new exe. When I plugged in the converter, it asked for ser2pl.sys. I had to dig quite a bit to find it - apparently Prolific's install program didn't put it in the C:\windows\system32\drivers directory. For those of you keeping score on versions of ser2pl.sys -the research I did on the Internet revealed that this is a common problem. When I finally did locate the file the version that comes with v1.1 of the Prolific install is 2.0.13.130. The version installed by v1.5 (the current package) is 2.1.27.183. I also contacted the vendor of the ActiveX control and they're no stranger to problems with USB->Serial converters. He recommended the following on the COM port properties configuration in Windows: 1. Disable the port's RX and TX FIFO. 2. Use settings in the control to assert the RTS line and negate the DTR line. Set the transmission delay to 0ms. Apparently there's a problem in the timing of these lines in regard to the actual data flow - they don't "line up". It seems to be working now, but I won't really know until field testing. Considering how many people use the converters, we may want to do some further research and put the results in a paper on the main website under the Technical Library page. If anybody wants it, I've put the older ser2pl.sys file here: ser2pl.zip v2.0.13.130 Joe T.

We are finishing up a VB6 program upgrade where we are adding a V130 using Modbus. The program was created to talk to an HP datalogger, and that instrument is still in place. It uses COM 1 on the computer. I bought a Modbus ActiveX to talk to the V130. The customer has a mix of Dell desktops and Inspiron laptops (with serial ports) so the second COM port for the V130 has to be run through a USB->Serial converter. We are using the official Unitronics Sunix -CS35 converter based on the Prolific PL2303 chipset. We have a routine that determines all the available COM ports and are able to select whatever port the USB converter assigns itself to. Now on to the problem.... During testing we found communications to the V130 to be unstable. The VB program first queries the V130 and then the HP. Communications to the V130 will work for a while and then lock up. We have to unplug the converter and then restart the program to get them back. We originally thought it was the ActiveX control, but then we swapped the V130 to COM1 on the motherboard and the HP to the USB converter and then the HP started hanging. All signs point to the driver for the converter. We are polling the devices every 5 seconds, so it's not like we're banging the ports too hard. I have installed the latest driver (1.5) from Prolific's website to no avail. I welcome any questions or suggestions to make our VB code more robust. I'm also curious if anyone has any experience with devices based on FTDI's chipset. Joe T.

If you're going to do the quadrature decoding in ladder logic then there's no need to use the high speed inputs. You can connect the encoder inputs to any two inputs and write logic to monitor both and see which one goes high first to determine direction. Emil- if the scan time of the PLC is 10 ms or so then the shortest pulse you can catch is 20 ms, which translates to a frequency of 50 Hz; still pretty slow for an encoder of any resolution. You really need to add a V200-18-E1B module to the back of the V570 to run the encoder to. Joe T.

In Visilogic- Read the Help on the COM INIT block. You'll want to use COM 2. Then read the Help on ALL the Protocol blocks. You will be using at least three of them. Then look at Help->Examples->Version 900->Project Examples->Communications->FB Protocol->V130_Display_String_from_Hyperterminal.vlp. The V120 and the V130 are the same at this level. After you've spent some time looking over the Help and looking at the examples come back with any questions. What you're looking to do is fairly easy after you understand how the pieces work. Joe T.

Can you post your code? Joe T.

We are running both the basic and enhanced webservers. Everything works fine inside the plant on the internal network as far as viewing from a browser. When we try to see the pages on a Blackberry on AT&T's network via VPN, we can only see the pages on the basic webserver, not the enhanced. Suggestions or comments? Thanks! Joe T.