Fanuc 21-T dead rs232 comms

[Jeremy Sawatzky]

Hello everyone

I have a new to me Daewoo Lynx 200B lathe, I need some assistance in troubleshooting the RS232 Communications. The machine uses a Fanuc 21-T control.

I would like to say I have tried absolutely everything under the sun to try and communicate with the machine but maybe I missed something.

I have tried the following and a million combinations of Baud rates, parity, stop bits, flow control, cables, com ports, software etc.

I cannot send or receive a single byte of information between the cnc and my pc.

My setup is a usb to serial db9 cable that I have confirmed works by using it to send files to and from a different machine. I then use a custom made db9-db25 rs 232 cable that again has been confirmed to work.

When I try to send files to the CNC, the leds on the usb serial cable blink indicating transfer is occuring but I dont believe that any data is being recorded by the cnc control. The menu on the Fanuc display blinks LSK like its waiting for data but nothing comes through. I have also tried sending a file from the machine to the control but again nothing comes through. It seems to me that the Fanuc board may just be toast. - as far as I know this machine came out of a running cnc shop.

Any suggestions?

 

[atex57]

Try to find a RS232 breakout box. It will have connectors for your cables and little jumper wires to set it up as straight through, null modem, etc. Had to do that for an orphan 3T machine. Do you have the books on the machine? Can you get the setup config that the previous company used? Or the cable?

Ed.

 

[FeinMecanix]

What program are you using to communicate with the control? I recommend the fanuc program transfer tool. You can really see what is happening with this software, it was the only thing that worked for me when I had a similar problem....

 

[Jeremy Sawatzky]

Try to find a RS232 breakout box. It will have connectors for your cables and little jumper wires to set it up as straight through, null modem, etc. Had to do that for an orphan 3T machine. Do you have the books on the machine? Can you get the setup config that the previous company used? Or the cable?

Ed.

I cant get any details on the previous setup unfortunately. I have half of the cable that they used as it was cut when the machine was removed. Im hopefully getting some manuals soon.

I think I will try and make a different cable config. The cable I have is a straight through but heck I will try crossing pins 2 and 3 from the db25 to db9 and see if that does anything.

 

[angelw]

Hello Jeremy,
List the parameters for RS232 protocol you have set at the control and the setting used, also what settings for the following you have in the PC Software:

1. Handshake Method
2. Number of Data Bits
3. Number of Stop Bits
4. Parity (odd, even, or none)
5 Baud Rate

Regards,

Bill

 

[Jeremy Sawatzky]

What program are you using to communicate with the control? I recommend the fanuc program transfer tool. You can really see what is happening with this software, it was the only thing that worked for me when I had a similar problem....

I have tried using DNC4U and another program cant remember the name of. Both indicate the file uploads and the leds on the usb cable are blinking so data is clearly being sent but I will try the fanuc transfer tool as well thanks

 

[angelw]

I cant get any details on the previous setup unfortunately. I have half of the cable that they used as it was cut when the machine was removed. Im hopefully getting some manuals soon.

I think I will try and make a different cable config. The cable I have is a straight through but heck I will try crossing pins 2 and 3 from the db25 to db9 and see if that does anything.

Whether the cable is configured as a Hardware Handshake, or Loop-back (Software Handshake) Null Modem Cable, when the connector at one end is DB9 and DB25 at the other, the Transmit/Receive pins will be connected as follows:

2 to 2 and 3 to 3. This is actually a cross over connection, because Transmit at one end is being connected to Receive at the other; accordingly, don't waste your time connecting these pins otherwise.

Regards,

Bill

 

[Jeremy Sawatzky]

Hello Jeremy,
List the parameters for RS232 protocol you have set at the control and the setting used, also what settings for the following you have in the PC Software:

1. Handshake Method
2. Number of Data Bits
3. Number of Stop Bits
4. Parity (odd, even, or none)
5 Baud Rate

Regards,

Bill

Hi Bill

1. Xon Xoff, none
2. 7 - also tried 8
3. 2 - also tried 1
4. Even
5. 2400, 4800, 9600

In the past I have been able to send a file from other machines to the DNC4U program wizard then the program records the correct settings so that I can send programs back. But I cant get a single byte to come out of the control it seems.

Thanks

 

[angelw]

I have tried using DNC4U and another program cant remember the name of. Both indicate the file uploads and the leds on the usb cable are blinking so data is clearly being sent but I will try the fanuc transfer tool as well thanks

Search for one of the dozens of Posts I've made, describing the correct cable configuration, control parameter settings and External Device software settings for successful program transfer with a Fanuc Control.

Regards,

Bill

 

[angelw]

Hi Bill

1. Xon Xoff, none
2. 7 - also tried 8
3. 2 - also tried 1
4. Even
5. 2400, 4800, 9600

In the past I have been able to send a file from other machines to the DNC4U program wizard then the program records the correct settings so that I can send programs back. But I cant get a single byte to come out of the control it seems.

Thanks

Set the following parameters at the control as shown:
Parameter
0020
bit 0 = 0
0100
bit 1 = 0
0101
bit 0 = 1
bit 3 = 0
bit 7 = 1
0102 = 0 (Use DC1 to DC4)
0103 = 11 (9600)(Baud rate)

Set the PC Software as follows:
Handshake Method = Software (Xon Xoff)
Data Bits = 7
Stop Bits = 2
Parity = Even
Baud Rate = 9600

Cable Configuration
Machine Side -------------------------------------- PC Side
DB25 Male ----------------------------------------- DB9 Female
1 ----- Shield Trace ---------------------------- Not Connected
2 ---------------------------------------------------------- 2
3 ---------------------------------------------------------- 3
4
| Bridged
5

6
|
8 All Bridged
|
20

7 ---------------------------------------------------------- 5

Regards,

Bill

 

[RJT]

Are you getting any error codes or any sign that it is trying to communicate (ready signal or something similar)? Are you sure the communications board is operable? We have had 2 boards fried by lightning strikes that acted like what you are describing. Can you contact the previous owner to see if they were using it and possibly get the parameters they were using?

 

[Jeremy Sawatzky]

Cable Configuration
Machine Side -------------------------------------- PC Side
DB25 Male ----------------------------------------- DB9 Female
1 ----- Shield Trace ---------------------------- Not Connected
2 ---------------------------------------------------------- 2
3 ---------------------------------------------------------- 3
Regards,

Bill

Bill, I tried 2-3 and 3-2 anyways and it worked. I can now send files to and from the machine... so relieved.

Any idea why this machine would be configured this way? I have poured over this machine and it doesnt look like anything was messed with...

Thanks everyone for all your help.

 

[angelw]

Bill, I tried 2-3 and 3-2 anyways and it worked. I can now send files to and from the machine... so relieved.

Any idea why this machine would be configured this way? I have poured over this machine and it doesnt look like anything was messed with...

Thanks everyone for all your help.

The following pictures show the conventional Pinout of DB9 and DB25 connectors. In a Null Modem setup, the Transmit and Receive pins have to be connected, end to end, irrespective of whether a pair of DB25, DB9, or one of each are used in the making of the cable.
Accordingly, to connect TX to RX and RX to TX when using a DB25 connector at one end and DB9 connector at the other, pins 2 to 2 and 3 to 3 have to be connected.

In the 40+ years I've been working with RS232 communication between Fanuc Controls and External Devices, including writing my own Editor/Comms Software, I've not seen one example that varies from the aforementioned.

You say that you have used the cable and USB to Serial converter on other machines to prove their integrity, with the DB25 to DB9 cable configured 2 to 2 and 3 to 3. That being the case, the only thing that is left is that the Fanuc Control is wired incorrectly. Also in 40+ years, I've not seen that.

Regards,

Bill

 

[Jeremy Sawatzky]

Yep I am baffled as well. But at this point its a 24 year old machine and I was making parts on it today so I am a happy camper.

 

[F35Machinist]

I like using the free program "Realterm" to send files over RS232. It has lots of control and a simple interface.