Need help making a serial cable

  • Thread starter Thread starter Steven C. Haber
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Steven C. Haber

I have several Seiko DPU-3445 portable printers. I need to use them for a
charity auction, and some of the machines I have available don't have
InfraRed capability.

The printer supports serial communication as well, but I can't figure out
the info from the manual to make a cable that works.

The printer has an RJ-11 interface (6-pins), and the manual describes them
as:

Pin 1: RXD
Pin 2: TXD
Pin 3: BUSY
Pin 4: CHK
Pin 5: SG
Pin 6: FG.

There's a diagram, so I know that on the printer side, the pins are numbered
right to left.

I've got the tools I need to crimp, and need the other end of the cable to
be a female DB9 connector to go to the serial output of a laptop.

I just don't know how to interpret the info in the Seiko manual to know
which pin from the printer matches which pin to the DB9 connector.

Any assistance (especially in the next few days) is greatly appreciated!

Steven
 
Steven C. Haber said:
I> The printer supports serial communication as well, but I can't figure out
the info from the manual to make a cable that works.

The printer has an RJ-11 interface (6-pins), and the manual describes them
as:

Pin 1: RXD
Pin 2: TXD
Pin 3: BUSY
Pin 4: CHK
Pin 5: SG
Pin 6: FG.
Click to expand...

Steve, don't know if this will help or not, but here are the standards for
the 9 pin.

1 - Carrier Detect
2 - Receive Data
3 - Transmit Data
4 - Data Terminal Ready
5 - Signal Ground
6 - Data Set Ready
7 - Request To Send
8 - Clear To Send
9 - Ring Indicator

Look closely at both sides of the DB9 and you will see the pin numbers on
the socket, they won't be in the order that you think.
If you manual gives you the DB9 pin numbers to use and you use colored wires
it should be no problem.

Bud
 
Steven C. Haber said:
I have several Seiko DPU-3445 portable printers. I need to use them for a
charity auction, and some of the machines I have available don't have
InfraRed capability.
Click to expand...
The printer supports serial communication as well, but I can't figure out
the info from the manual to make a cable that works.

The printer has an RJ-11 interface (6-pins), and the manual describes them
as:

Pin 1: RXD
Pin 2: TXD
Pin 3: BUSY
Pin 4: CHK
Pin 5: SG
Pin 6: FG.
Click to expand...

Okay, that's some kind of serial. SG may be signal ground and FG may be
frame ground. "BUSY" and "CHK" ... I'm not sure what those would be in
standard RS-232. Some web searching turned up this:

http://www.avdcs.co.uk/tech/faq/fa_smart/slp2000.html

But it's for other models of Seiko printers, and it still doesn't have
pinouts on the RJ11 end. It suggests that BUSY and CHK are DTR and DSR,
or the other way around. Hooking them up wrong wouldn't hurt anything
in normal RS-232 (although it wouldn't work), but that may not be the
case with this printer.

It might be worth trying a cable without BUSY and CHK connected. Set
the computer to 9600, N, 8, 1 and see if it will print. If you see data
problems due to buffer overruns, then try hooking up the two other
signals.

Or call Seiko and try to find someone who knows just how the cable
should be wired.
 
Thanks! It's the BUSY and CHK that were tripping me up. I've never seen that
terminology.

I've found the standard pins for the DB9, it was matching that up to Seiko's
unusual terminology that might be getting to me. I'll try what you suggest
and see what happens.

I purchased a cheap $10 cable for their label printers, thinking it might
use the same protocol, but it doesn't, but at least I can cut the cable and
match wires different ways (using my handy voltage tester) until I find
something that works.

I've made a request from Seiko through their website. Haven't had time yet
to try getting to them by phone to see if I can find the right person.
 
Thanks again for your assistance.

I was able to make a working cable using only 3 wires:

Seiko's Pin 1 (RXD) to DB9 pin 3, TXD,
Seiko's Pin 2 (TXD) to DB9 pin 2, RXD, and
Seiko's Pin 5 (SG) to DB9 pin 5, GND.

All appears to work fine at 38400 bps (the printer's maximum serial speed).
 
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