I am a first year teacher and seem to have a.... LARGE problem. My shop is equipped with a HAAS HL-2 lathe. Since setting foot in the shop nearly two months ago, the students and I have made every attempt to send files to the lathe with no luck. The previous instructor had no problems with the machine.

We have used different computers.
We have tested the communication cable.
We have the settings on the sending computer matching the lathe.


we prepare the lathe to receive,,,, send the file.... the lathe screen maintains a "waiting" command on the bottom of the screen.

please submit any questions, suggestions, or otherwise. To hire someone to come and diagnose it is at least $1k..... because of our loacation. I am willing to try nearly anything...

THANKS!

You wouldn't be using the computer printer port as a comm port, would you? ;)

Has the machine ever had a service technician working on it between the time the previous instructor was on the scene, before you arrived? Has anyone fiddled with the parameter settings? I did have comm trouble on my Haas mill, but this occurred after a major upgrade, including some new circuit boards, and there was a particular parameter setting that was not in the regular comm setting area, that had to be altered. I would not think this necessary in your machine's case, unless a major service had occurred.

The machine was not touched over the summer. I have had several students who ran the machine day in and out try to communicate to the lathe. We are using the correct port. We have tried other working computers. No luck. I will look over all the parameters once again.... in a few hours when i wake up.

051011-0758 EST USA

allen d:

First go to my web site www.beta-a2.com then pick the E232 PHOTOS page and find the connector wiring diagram and troubleshooting area. The wiring diagram is correct for the HAAS side, but to connect to a 9 pin PC connector certain connections at the 9 pin end need to be interchanged. See the written comments for this information.

To troubleshoot your problem start by determining if the HAAS is sending data out.

Set your parameters to 7 data bits, Even parity, XON/XOFF handshake (HAAS calls it synchronization), and 1 stop bit. For now use 9600 baud.

There are two RS232 connectors on the cabinet side. Normally the top connector is COM1 (COM1 is my terminology for the serial data communication channel. The other connector COM2 is for a rotary table.)

Connect a voltmeter (I prefer a Simpson 260, 270 or equivalent, but a digital can be used preferably set on a fixed range.) black lead (common, -) to pin 7 of the HAAS 25 pin connector. Pin 7 is signal ground (I prefer the word common instead of ground unless we are talking about earth ground. A common may be connected to earth ground, but it is not necessarily connected.)

Pin 2 is the TxD output from the HAAS connector. Connect the red wire (+) here. With no data being sent the meter reading should be about -10 v.

Pick any program in the HAAS, preferably 10k bytes or more, and send it (ALL is a good choice). The meter reading should float around +/-1 v.

If the voltage stays around the -10, then this connector has no data being sent out. In that case check the output from the other connector.

Pins 6, 8, 20 are "do not care" for HAAS. Internally in HAAS these are connected together but go nowhere else.

Pins 4 and 5 are RTS and CTS handshake lines but CTS is not tested by HAAS in the XON/XOFF mode, contrary to what a HAAS tech told me one day.

If neither connector shows data output on pin 2 relative to pin 7, then there is an internal problem in HAAS.

Just to make sure that your machine is not different jumper pin 4 to 5 and test for data transfer again. Note pin 4 (RTS) should be high (logic 1, +10 v). Note the data lines TxD, RxD employ negative logic (meaning a logic 0 is +10v v, and logic 1 is -10v).

With pin 4 connected to pin 5 you can change HAAS to hardware handshake (RTS/CTS) and again try sending.

I have had one customer that had RS232 hang because of a thermal problem in the RS232 area. Opening the cabinet door and using an external fan corrected the problem.

If you can determine that HAAS is sending data, then the next step is to get the PC to receive this data.

Also when the HAAS is not transmitting do a short circuit current test on TxD. This should be about 10 ma.

.

This is the wiring I used on the Haas Mini mills.


The cable connector for Haas Mills

PC DB9 .............Haas Mill DB25
--------------------------------

2---------------------2
3---------------------3
8---------------------4
7---------------------5
5----------|----------7
................|----------1

1-4-6 ................6-8-20

-------------------------------

GAR,

That wiring diagram is misleading. The common wiring has the pins 2 & 3 and 7 & 8 turned around.

051011-1745 EST USA

WayneHill:

My circuit diagram is not intended for PC to HAAS connection, but for our E232 to HAAS connection.

This I stated in my previous post, and I indicated that for connection to a PC that following the diagram I verbally described the wires to be interchanged at the PC 9 pin connector.

.

051011-2111 EST USA

allen_d:

The reason to try to receive data from HAAS as the first troubleshooting step is because this is the easiest way to determine that parameters are working correctly and at least some of the common chips are at least partially working. Also it is easier to use different devices to detect if data is being transmitted.

Once you know for sure which connector is the correct one of the two and that HAAS can send data, then you turn around your viewpoint and check that your source is sending data.

After you know you have serial data at HAAS coming from the computer and HAAS is still not receiving, then you have a much narrower area to look for the problem.

.

Pin 2 is the TxD output from the HAAS connector. Connect the red wire (+) here. With no data being sent the meter reading should be about -10 v.
The voltage was -3.36v.


Pick any program in the HAAS, preferably 10k bytes or more, and send it (ALL is a good choice). The meter reading should float around +/-1 v.
The voltage dropped to ~ -2v.


These were the only test i managed to perform today. I had problems uploading programs from a floppy.... (none were on the machine....) Is the fact that i have a voltage of -3.36 and indicator that i have a communication problem within the lathe?

I have considered getting a serial port tester... and understand radioshack carries one. Is that necessary?

THANKS for your guys help. This has been very stressful.

051012-0622 EST USA

allen_d:

It appears you have a problem within HAAS.

The RadioShack tester will not provide information as good as the meter because it is not quantitive. But it does provide simultaneous information on all channels.

You may have a power supply problem since you also had floppy problems.

I want to restate the voltage measurement tests to make sure you are doing what I expect.

Use a DC voltmeter, and DC milliampere meter. A Simpson 260 is both and also an AC meter. The Simpson 260 in AC position will read a DC voltage but the calibration will be incorrect. A typical Fluke meter removes the DC component when in AC position.

The voltage measurement from TxD on the HAAS is from pin 2 (TxD) to pin 7 (signal common --- this is thru a 100 ohm resistor to power supply common), also try this measurement from pin 2 to pin 1 (shield --- this is directly tied to the +/-12 vdc power supply common and to the machine frame).

With nothing connected into the HAAS RS232 connector except the meter the voltage should be about -10 v. -3.36 is grossly incorrect. This is only 0.36 v above the voltage threshold defined in the RS232 spec for a logic 1 signal. Put your meter in MA mode and measure the short circuit current from pin 2 to 7. Should be about 10 ma.

Since your reading when data is being sent is only about -2 volts this implies no +12 supply. Basically the RS232 driver chip, typically a 1488, is supplied by a +/-12 v supply and when it is switched between a logic 1 and 0 the output should change from about +10 to -10 v.

The test from pin 1 to 2 may tell us more.

In the HAAS control is a Low Voltage Power Supply that supplies +/-5 and +/-12 and may look like a switching power supply from a PC. Generally these supplies have to have a minimum load to work correctly. So you can not just unplug the load to check the power supply.

In one of our VF3s there is a board just below said power supply that has some open terminals labeled +/- 12. These are closely spaced and if you use these to check voltage be very careful to avoid shorting. The machine cabinet should be sufficient for the meter common lead.

If these voltages are correct, then there maybe problems with the 1488 and 1489 chips or their equivalent.

.

THANKS for your support. Here are my tests from today. I would like to begin in mentioning that the multimeter that i am using is a Craftsman 82026. We have 2 of them, and i have used them both to ensure that the readings that I am getting are indeed correct.

The voltage measurement from TxD on the HAAS is from pin 2 (TxD) to pin 7
The voltage today read -3.40

also try this measurement from pin 2 to pin 1
This reading yielded -3.80.

In the HAAS control is a Low Voltage Power Supply that supplies +/-5 and +/-12
I tested these. The readings were 14 and 6.

meter in MA mode and measure the short circuit current from pin 2 to 7
I placed my meter in 20mA, and tested this. However i didn't get a reading.

As a conclusion of this testing, I am lead to understand that my RS 232 driver chip is not working. This being said, I would need an entire new motherboard. Any suggestions?

051012-1830 EST USA

allen_d:

There should be protective circuits on the small pc board directly connected to the RS232 connector. Each I/O pin that is used (2, 3, 4, 5, 6, 7, 8, and 20) except pin 1 has a 100 ohm resistor from the pin to the RS232 interface chip. At the end of each resistor that goes to the interface is a bi-directional transient limiter. This has about a +/- 18 clamp point. I believe I previously mentioned performing a test on a similar circuiit by applying 120 vac to the resistor and that the resistor was destroyed with no damage to the transient limiter.

Your voltages measured on the power supply pins are suspect. Either the meter is a problem or the power supply voltage is high. Tonight I can not check our machine but I will in the morning. The 6 v reading on a 5 v supply might mean other circuit damage.

My off hand guess is that 120 vac applied to an RS232 pin would not have damaged a 1488 or 1489 chip. I suggest that you measure the voltage between pin 2 and 1 on the other RS232 connector. Each RS232 connector is going to connect to one 1488 and one 1489 (these are quad devices). Thus different chips are associated with the other connector. This assumes that these or their equivalent are the chips that HAAS uses. Is there an intermeadiate voltage to the I/O pin that would destroy the transisent limiter and not the resistor? I do not know.

You can check the resistors on the RS232 connector with your ohmmeter.

I know nothing about your Sears meter. A brand new fresh standard AA battery should be very close to 1.55 v. Try one to check the meter.

Five volt TTL chips are not designed to operate at 6 v. The TI maximum rating is 5.5 v. CMOS is a different story. How far above maximum rating you can operate without damage is dependent on many factors.

I believe it is correct that the RS232 circuitry is on the main processor board. Not cheap.

.

051013-0928 EST USA

allen_d:

On our 1998 VF3 the voltages are: +5 at 4.969, +12 at 11.929, and -12 at -12.048.

I measured some never used batteries this morning.

3.30 v CR2025 by Eveready (new name is Energizer) very old - predates name change
3.31 v ECR2025 by Energizer - much newer
3.27 v 2032 by Duracell - a number of years old
Note lithium batteries have a very low self discharge rate. That is why the very old one is so near the newer one.

The following are alkaline.
1.622 AA Energizer a few months old
1.623
1.620
1.624 all the same batch

1.606 D Energizer about 1 yr old
1.609
1.608
1.606 all the same batch

1.582 C Rayovac more than a year old
1.582 same batch

1.572 EPX76 Energizer siliver-oxide

I think an Energizer lithium would be the best voltage reference.

Looks like your power supply is at least one of your problems, if your meter is correct. You probably have more than serial port problems. At this point you may need a HAAS service person.

.

051013-1524 EST USA

allen_d:

If in fact you have a defective power supply and this has damaged components, then this is a good illustration of why there should be a crowbar on each output.

When power supplies are so cheap, and a failure can cost lots of money, then the small cost of crowbars would be worth while.

On our HAAS machines (5 of them) we have never had a power supply failure. However, your problem has me considering the addition of protection on our machines.

A crow bar is essentially an SCR and zener diode, and maybe a few other components, or an equivalent function, that on an overvoltage shorts (crowbar) the output of the power supply. It is assumed that the power supply will in some way current limit. The current limit might be a fuse or the transformer winding might burn out. This is better than destroying other expensive circuits.

14 volts on the 1488 should not be a problem, but 6 v instead of 5 on the 5 v portion of the chip might fail the chip.

.

gar...

i made a switch and got a Fluke73III. I was uncertain about the crapsman.

I didn't have much time for testing today... though i retested the low voltage power supply. The following are the results.

12.10
12.10

5.03
5.03

On the top serial port... from pins 2-7 yielded -3.230v.
On the top serial port... from pins 1-2 yielded 3.214v.

On the bottom serial port... from pins 1-2 yielded 2.755v.

I do not know where to find the resistors on the RS232 connector. I am assuming i have to pull the cover off next to the serial ports. I haven't done this yet...

I have taken a couple of pictures that i hope to attach to this message. They are from the back of the machine. They don't mean too much, though i am guessing them to be similar to your VF3.

I don't think i can thank you enough.
Allen.

051013-1935 EST USA

allen_d:

Nice photos.

Photo 10-12-2005 009.jpg shows the small pc boards where the 100 ohm resistors and transient limiters are located.

The voltage results from the power supply are very good and therefore no power supply problem.

Your other voltage results are rather strange, but you did not put the black meter lead on pin 1. So 2 to 1 is -3.214, and 2 to 7 is -3.230. Thus pin 7 is more negative than 1 by 0.016 volts.

Pin 1 should be be a nearly direct connection to the machine cabinet ( I measure about 0.1 ohm), electrical safety ground (the ground strip at the top right inside the cabinet), and the common terminal of the +/-12 and 5 supply. An ohmmeter check should verify this as being nearly zero resistance, and the dc voltage from machine chassis to pin 1 should be next to zero. But with no current source to pin 1 the voltage measurement may not be useful.

Pin 7 should connect to pin 1 thru a 100 ohm resistor (must be measured with machine power off). At least in an indirect fashion pin 7 should connect to pin 1. With power on I measure +0.018 v from pin 2 to 1. Whereas your two measurements imply -0.016 v.

To remove the RS232 connector board unscrew the two hex posts. These have on the inside a 4-40 stud that screws into a nut on the backside of the connector shell. Once you have this removed, then you can check the resistors. Also on the transient limiter side of the resistor check the voltage to machine chassis. You might want to run a wire from the top ground strip to serve as your common meter measurement position.

Check the resistance of the resistors with the power off.

Whenever power is on make sure that this RS232 connector pc board can not short to anything. Also remember that in the electrical enclosure there is exposed high voltage, both ac and dc. Be very careful.

If the pin 2 voltage is about the same on either side of the resistor, then unplug the board from the ribbon cable. Use a small wire on the meter probe to test the voltage at the end of the ribbon connector using the previously mentioned wire from the ground strip as the meter common.

If the voltage is still low, then romove the sheetmetal cover over the processor board, and revove the ribbon cable from the processor board and check the appropriate pin on the processor board corresponding with pin 2, also do this for pin 4. In the rest state pin 4 is normally about +10 v on HAAS. I read +11.39 on pin 4 and -11.27 on pin 2.

If your voltages are low at the processor board with no load, then the problem is in the processor board, or thereabouts.

Most likely there is some sort of common problem, and probably at the processor board, because you get similar results on both RS232 connectors.

.

gar...
i was uable to perform any tests today because of my schedule. I'll test on monday.
allen