Hello,
I have been trying to get my "new" HP 7475A plotter to work with my laptop. I am running Windows 98SE and using AutoCAD 2000. I configured the dip settings to the following:
Baud=9600
Parity=None
Operating Environment=Direct
Paper Size=English 11x17 (B size)

The plotter uses the RS232-C/CCITT V.24 port and did not come with a cable. Through HP's website,they say to use HP cable P/N 24542G which they say is simply a DB 9 female plug to a DB25 male plug which they call a "Null Modem" serial cable. I purchased a generic serial cable at my local Fry's.

Finally I tried to configure the 9 pin RS232 com1 serial port properties on my Toshiba 490XCDT Laptop with the settings the same as the above DIP settings, 1 stop bit and the hardware flow control at Xon/Xoff. When I tried to print a sample from word pad or AutoCAD, the computer spooled but plotter did not respond at all! Same for "None" and "Hardware" flow setting. I have tested the plotter and it printed test page. What should I do, change or try???? I appreciate any help I can get! (chair)

Hello,
I have been trying to get my "new" HP 7475A plotter to work with my laptop. I am running Windows 98SE and using AutoCAD 2000. I configured the dip settings to the following:
Baud=9600
Parity=None
Operating Environment=Direct
Paper Size=English 11x17 (B size)

The plotter uses the RS232-C/CCITT V.24 port and did not come with a cable. Through HP's website,they say to use HP cable P/N 24542G which they say is simply a DB 9 female plug to a DB25 male plug which they call a "Null Modem" serial cable. I purchased a generic serial cable at my local Fry's.

Finally I tried to configure the 9 pin RS232 com1 serial port properties on my Toshiba 490XCDT Laptop with the settings the same as the above DIP settings, 1 stop bit and the hardware flow control at Xon/Xoff. When I tried to print a sample from word pad or AutoCAD, the computer spooled but plotter did not respond at all! Same for "None" and "Hardware" flow setting. I have tested the plotter and it printed test page. What should I do, change or try???? I appreciate any help I can get! (chair)

I went thru this some time ago. I haven't used it in some time but there are some switches that have to be set up as I remember it. And the serial cable wasn't as simple as it should have been. Have you searched the net for information? I may have a manual somewhere if all else fails but I have no idea where it is. There were several of us having a go at this at the time and we all had more trouble than expected. If you can't get it going email me and I will try and find a manual and get you the information. I own a 7475 and have acess to two of them at work. But at work we used the HPIB port.

Garry

OKAY.. I have this same plotter up in my attic, and had a heck of a time getting it to work.. the secret is the NULL modem cable part.. I standard serial cable will *NOT* work.. you need a NULL MODEM adapter to put on it.. this reverses pins 2 & 3, and maybe some others.. it basically reverses all the send & recieve wires.

You will probably have to search a junk parts bin at a computer store, or find a *KNOWLEDGEABLE* person in a computer store to help you find one.. try to finda computer tech who has been in the field for 10-15 years.. he will rememebr the olden days when these items were standard!

Mention BBS's to him, and hear him talk about the glory days back then.. hahaha

Eddie

The most fool-proof of set-ups to initially try is:

8 Data Bits
2 Stop Bits
No Parity
No HandShake
And, of course, Baud Rates set the same (on the slow side to be safe)

For the cable:

DB9 DB25
TX <-> RX (Pin 3)
RX <-> TX (Pin 2)
GND <-> GND (Pin 7)

I am recalling the pin outs for the DB25 from the top of my head and for the DB9 I can't remember - so check me on this.

For checking, if you have a volt/ohm meter to use, do this:

First check your cable with the ohm meter by making sure the TX pin on one end is connected to the RX pin on the other and vise-versa. Then check GND to GND.

To check if data is being transmitted over the cable, plug the cable into the computer only. On the hanging end that should plug into the plotter, and, with your multi-meter in voltage mode, put the Pos probe on the RX pin and the Gnd probe on the GND pin. As I recall, you should read a negative voltage while not transmitting - that is if it is true RS-232, if not true RS-232 the voltage signals for marks and spaces will probably swing between zero and probably 5V when transmitting. Anyway, you should read some static voltage level while not transmitting.

Now, with your volt meter probes on the pins as described above and reading some static voltage value, send a long file out the computer's RS-232 program. If is transmitting data, you should see a fluctuating value for the voltage - this is the volt meter trying to read the changing voltage/bit values that are being transmitted.

If you don't have a volt meter, try this: with the cable connected as described above (to the computer only) short the TX and RX Pins together on the dangling end of the cable. If you have a modem program, type some characters in and see if they echo back to the screen. If you don't have a modem program, I think Hyperterm still comes with windows and will work for this test.

Hope this helps,

plm

Here's a site, shows the various wire config's I used it to build all my own cables, they work great.
goto a local electronics store and buy the connector,pins(male and female) and a roll of 9 wire small enough to make as many cables as needed.
I like to crimp the pins to the cables and before pushing them into the actual connectors i place them on the devices they will be used on and confirm the 'pinout', after I write down the wire colours to pin numbers and then assembly them onto the connectors.

http://www.jspayne.com/io/schematics.html

Try this link for HP Designjet Printers - Serial Cable Pin Outs:

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?locale=en_US&taskId=120&prodSeriesId=25257&prodTypeId=18972&objectID=bpp01037

I think you might be able to find the serial info here

http://www.luberth.com/help/HP_7475_Graphics_Plotter_interfacing_and_programming_manual/


Jim
www.embeddedtronics.com

I have had a problem to with the hp7475A one site looked like cable and wired it and as you read into it coped out to xon and xoff protocall and you have to send commnad to plotter to turn on , I wated full hardware handshake, got to work great on compaque compputer 9 pin and then went to intel 9 pin computer here and garbage with eagle pcb. at 9600baud, hate that when it happens, I just previously cut away plastic to take tall pen and honed out a few old pens with a harbor frieght dremel toy that came with 104 tools for 15 bucks, ha it works good, chinese mut be doing it. want to make money open a harbor frieght store, people coming like bees to honey. enough of that. well xon xoff is a good too to check with but when pen is down and at 1200 baud it can be bad like pen feeding. enough for Umor, but its fun. well the pcb laser or plotter delema goes on till I get a saegler 318-2 red pen to try. Sharpe on pcb, heard some bad and good. got .3 sharpies now. see ya

First absoluty MUST have a null modem either cable or a null modem adapter connected to your regular cable else you are dead in the water.

Now, turn the plotter around so you are facing the back. All switches shall now be on your LEFT.

B1=F
B2=B
B3=F
B4=B
A2=F
US=B
Y=F
S1=F
S2=F

F defines switch pushed away from you.
B defines switch drawn back toward you.

These settings work fine for me BUT it is under my cam program working in DOS.

Hope it helps you.
Fran

I have the HP 7475a plotter wanting to convert to a vinyl cutter. It has a centronics-24 pin connector on it (or known as an IEEE-488 cable). I want to be able to hook this to my windows PC... Is this possible with an adapter, null modem or custom cable fab?

Could not find much info about this connector to PC

Don't care if I go to a serial, parallel, db9 etc connector.


THanks for any help.

K

Hi, I have a ColorPro plotter and I got it work just fine.

First you need a 25 pin to 9 pin serial adapter. Then use a NULL Modem cable going to the PC.

I found that if you can save out *.PLT files from your CAD software, you can send them directly to the plotter from a DOS command prompt (yes, even in 2K or XP) by doing the following:

1. Open a Command prompt

2. Type "mode COM1:9600,N,8,1,P"

3. Then type "Copy <path and filename of *.PLT file> COM1" and press enter


This sends the plot file directly to the plotter.

Myself, I've written a small bit of software to handle showing me a preview of the vector drawing on the plotter (HP plotters are 1100 plot units per inch or something like that)

-niko

my cable is a 24 pin, will the 25pin to 9pin cable work?

Thanks alot

Oops. I didn't read your post correctly. You have a centronics connector. This is a parallel port connection.

You should be able to use a centronics parallel port cable to connect to it. Then you might be able to follow the same instructions I noted above, on how to send a Plot file directly to it.


See this page:

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=115&prodSeriesId=25257&prodTypeId=18972&objectID=bpp01036

-niko

I have a 7475a running here on xp with a 9 pin on com1: and a 25 way on the plotter, do you want me to take it apart and see how its wired, its also working the calcomp model 83 I could not get going last week.

(Now I'm looking for something to help me plot *.bmp files easily)

I have an old DMP 60 from Houston Instruments.I bought a program from WinLine and It works perfetly using xp.I notice that the software supports the hp 7475a plotter.www.winline.com. (http://www.winline.com.No) No affiliation .

I have the centronics 24 pin, don't know how I can wire this up to my computer, any help?

I have the centronics 24 pin, don't know how I can wire this up to my computer, any help?

Impossible.

(or no doubt lots more money)

really yea thats what I was figuring, need a new computer pci board or something crazy...

dont you have a 9 pin serial ?

On my computer? yes 9pin serial, but on the plotter, it is a 24pin centronics output...

I think someone (in yahoo homebrewpcb group) said that they came in 25 pin serial or some 'other' HP own standard which requires a special interface card, its like an offstandard scsi with ability for different devices on one port, without the matching card, its a non starter.

I think someone (in yahoo homebrewpcb group) said that they came in 25 pin serial or some 'other' HP own standard which requires a special interface card, its like an offstandard scsi with ability for different devices on one port, without the matching card, its a non starter.

Well I am not sure what he is talking about but I suspect what he has is a plotter with a IEE488/HPIB interface. If he does then PC cards are readily available though pricey new. This is an interface buss that when it came out went by the name HPIB for Hewlet Packard Interface Buss. In those days HP made much test equipment and few computers. There was an even earlier varrient called the ASCII buss. The HPIB became a instrumnet control standard buss and was adopted as the IEE488 buss and is still widely used as an instrument control interface. There are cards from several vendors for the PC, the most popular being the National semiconductor card. (Or it was a few years back, things change). BTW the IEE488 bus also is sometimes called the GPIB for general purpose interface buss.

I suspect that fro the right surplus place a replacement interface would be available that you could install in your plotter to make it a serial interface. Many of the next generation plotters came with three interfaces, The Printer parallel, Serial, and IEE488..

Garry