Xerox WC 7655 and SP (Screening Puzzle)

Ahoy all!

The almost-100%-happy owner of a WC 7655, that's who i am, a wc that was bought refurbished at less than one third of the price of a DC 242 in the middle of this "crisis" (so pls do not reply saying that i should have bought dc, it was either wc refurbished or nothing - lol)

so lets get to the point.

7655 is as we all know the same engine with dc but with less capabilities given to the user. so we are not going to discuss what they should have given to the wc, but why it is not working as it should be (according to my brain's assumptions).

lets see the first piece of the puzzle.

wc 7655 prints mostly with a screen frequency using LINE at 45 degrees. BUT sometimes, it does print with a DOT screen. i have done zillion of tests, couldnt be able to understand whats happening. for example, a square with 20% cyan is printed as LINE but a 20% magenta is printed as DOT. what? yes! ON THE SAME PAGE! and i thought screening was about the whole page...



so the game here is to find out how can we select DOT or LINE whenever WE want and not according to machine's unknown way of deciding.

now let's see what the PPD file that Xerox supplies says. Remember that PPD files are describing the truly given capabilities of a machine.

Code:

*% Halftone Info

*DefaultHalftoneType: 3
*ScreenFreq: "106.0"
*ScreenAngle: "45.0"
*DefaultScreenProc: Dot
*ScreenProc Dot: "
        { abs exch abs 2 copy add 1 gt { 1 sub dup mul exch 1 sub dup mul add 1 sub }
        { dup mul exch dup mul add 1 exch sub } ifelse }
"
*End
*ScreenProc Line: "
        { pop }
"
*End
*ScreenProc Ellipse: "
        { dup 5 mul 8 div mul exch dup mul exch add sqrt 1 exch sub }
"
*End
*DefaultTransfer: Null
*Transfer Null: "
        { }
"
*End
*Transfer Null.Inverse: "
       { 1 exch sub }
"
*End

This implies that the 7655 is capable of printing with DOT, LINE and ELLIPSE, unless i am completely wrong.

Selecting the screen frequency detail from programs such as CorelDraw doesnt have an effect. Neither does have an effect if i manually change the .prn or .ps file and then send it to printer.

Does anyone would like to discuss this with me? throw a hint, or perhaps a rock to my head would solve the issue. lol

thank u all for your time!

have a nice day

minas n. miliaras
athens, greece
http://plus.ma

 

ok we do have an update. at least i found out when this mixed screening occurs.

I have just realised that this wicked phenomena (of having dot + line screen on one page)
occurs when one uses the PS 7655 driver and prints in Enhanced Mode.

Xerox officially say that it is better to use "Global Driver". So with that, even on Enhanced Mode
one does not get the double trouble effect. Everything is printed with LINE screen...

That means that it was a bug that caused the double screening. But if that is possible, then it could
be possible to have different screens on one page? i am puzzled! anyhow, that is not our concern
right now.

so, does anyone know or have any hint on how to print on different screens?
Xerox says they dont know, they will have to check out and call me next week.

thx

minas

 

Could you make a backup and delete the portions of ppd mentioning anything but dot.

My assumption being dot is the desired preference.

Ken

 

thx Ken

yes, dot is the desired preference.
i have already tried to leave a ppd only with dot screening but nothing happened.

in fact, now that the dot+line seems as the result of a bug of the driver,
the machine seems to completely ignore what is being said at the .ps file
regarding screening:

that is the only screen declaration at the .ps file:

Code:

/@dot{dup 5 mul 8 div mul exch dup mul exch add sqrt 1 exch sub}
bd

then it asks for 106 lpi 45 degrees DOT:

Code:

wCorel3Dict begin
@BeginSysCorelDict
/LV 3 def @PL
-0.13805 0.05499 Tl
@ssa
106 45 /@dot @D
1.00 setflat
/$fst 256 def
userdict begin
end

either the machine is somehow 'locked' to produce line screening, but why, if they have done that, shouldnt they decide to stick to dot screening?

either xerox supplies us with faulty driver and probably? faulty ppd that describes three types of screens when the machine only produces one

either coreldraw isnt producing correct postscript description for the screening and 7655's controller ignores it. does anyone know if the above postscript code is ok and valid for postscript 3?

thx

minas

 

Why does Xerox have a 242 and 252 machine where 10 copies a minute faster is because of some minor instruction to make one machine run slower on 8.5 x 11 - to charge more of course.

However I have seen buggy print drivers before because manufactureres introduce there extras like saved settings but then also introduce some error. If you are using Windows XP I suggest trying to download Adobes PS driver from Adobe.com it is version 1.06 . You use it to install a new printer, it will ask for your PPD in the process, perhaps then only having the dot screen selected will work. Also check with your Xerox tech - sometimes they have access to software switches in the machine that can override settings, maybe they can select dotscreen only.

The drawback is you will see all functions in a list and you won't have option of saved settings but as its not using any of manufacturers bells and whistles it may work as it should. You do have the option of saving as more than 1 printer and using different preferences for each - I've done this to have a Greyscale and a separate color printer install (of the same printer)
Settings must be made outside of any program to retain. If sharing a printer you must first go to Properties, then preferences for setting sharing preferences.


Also what happens with setting driver or Corel as PS2 output. Sometimes errors go away by switching from PS3 to PS2.

Regards Corel, in past I found with EFI Fiery one should not Optimize fountain fills or they actually could have artifacts, it also seemed the LPI setting was ignored when printing to a Fiery.

Ken

 

thank u Ken, i will try to use adobe's ps driver, that seems a great idea,
leaving on the ppd, prior installation, only the info about dot screen.

and yes, they surely are wicked, in a way that they charge extra
for letting the wc 7655 to work as a network scanner. i mean, come on
it already works as a photocopier, so there shouldnt be any cost of
sending it to the network instead of printing. but then they will say
its a whole kit (that costs more than 400 euros) consisting of a sim
silly security card and a computer card that is to be installed inside
the controller, with another cable from the card to the machine,
uplifting the count of cables that connect controller and the machine
to 3! (excluding power cable!) LOL

its a common practice: great minds create great machines, then the
'our nerves destructing' department of the huge company starts splitting the
machine in... versions

but then i should mention that i love this machine already and it hasnt
been a month since i bought it. prints are amazing and productivity
is stable. and i want to keep that fingers crossed so that it will print
dot screen to me!

thank u once more
i will give it a try
and post a feedback

have a nice sunday!

minas

 

They all do it this way, canon, konica, etc.; a bit frustrating if your budget only allows the detuned machine to know that you have something that is very close to capeable of faster with only that one or two things changed, but at the same time, look on the bright side. If your budget only allows the slower (or less featured) version, you still get a lot of the engineering that went into the more expensive unit. You also get a greater commonality of parts which is beneficial in the long-run.

 

The Adobe 1.06 installer will likely only work if the 7665 is genuine Adobe postscript.

I guess while you are at it you could also look into using a Fiery or Creo print driver. The Fiery 242, 252, 260 series gives a choice of dot or line screen. The default is line but if one sets in preferences outside of program it can stay as Dot, it also has regular or enhanced quality check box, maybe a choice of enhanced and dot screen?

Probably it will create all sorts of errors but one doesn't know till they try, if successful with dot screen maybe one could graft the section of ppd into the 7665 driver?.

For Windows 7 we've been using a 64 bit Doc 260 Windows Server driver on our 240 which is Graphical and allows saving file settings, normally it works pretty good but there was a Publisher file that had screening not show at all, change to the regular 64 bit driver that looks like a Adobe 1.06 list with no graphical interface and the Publisher file printed as per monitor, so now we keep both installed same IP port different port name so both printers show in the printer list. Just one of the problems of moving to 64 bit Windows 7 but of course the advantage is breaking the 4 GIG limit for RAM.

Ken

 

of course (but we humans are known of never stop asking for more... your approach is also correct, it depends how one sees the half empty/full glass
i am extremely pleased by this machine, really. and i wasnt into liking xerox,
no, not at all, i would prefer a canon, that is deciding by brand name that doesnt
really mean anything, anyway

thx. i have already tried that with no results. i will definately try the adobe's
ppd idea first thing monday morning. xerox declares : "[7655] ... provide genuine Adobe PostScript Level 3" (copied from a pdf)

minas

ps: i am making the videos for a theatrical play/video art project and havent slept for the past two days. still, on top of my mind is the dot screening! am i wicked or what LOL

 

of course neither way it works. the xerox representative's technicians here doesnt seem to even know what the heck i am talking about, or they simply dont know how to answer.

i guess the machine is somehow "locked" to produce only line screening. then, there is a bug in the printer driver (that is solved in the global one) that produces dot screen only on magenta on "enhanced" mode.

we shall assume that xerox gives a .ppd that describes three screenings and that it was produced without knowing they were going to lock it? i am so confused!

 

To confuse the issue further Xerox has a Universal driver but
also a Universal Mobile Driver http://www.office.xerox.com/software-solutions/mobile-printer-driver/enus.html both in 32 and 64 bit

Plus you haven't told us how a PCL driver works. Just a guess here but most times they will have a PCL driver as well. On our Canon IR6000 we use the PCL driver instead of Postscript because its faster at variable data. I've also heard of instances where screening is better. Have you checked the PCL driver out for screening and features?

http://tinyurl.com/co7bwn


Ken Graham
CommunityPrinters.com
Dawson Creek BC

 

A new possible workaround - the Xerox Universal Print Driver, it has a PASS Through feature where I think the postscript may be created at the workstation and image fed bypassing the RIP entirely. This driver is available in 32 and 64 bit.

White Paper (manual) here http://www.office.xerox.com/latest/SFTWP-02.PDF

I've attached below my success and pitfalls setting it up with the otherwise unsupported Docucolor 12 in the 64 bit Windows 7 Environment.

A bit of information on install on our Windows 7, 64 bit system - this Universal PS Xerox driver did not automatically recognize our Docucolor 12, probably because the RIP is not Xerox but EFI Fiery.

12 megs downloads to begin with and should be saved for future. On initial install you may press one of the screen menu buttons and install by IP or name, I set fixed IP's on my servers so used that and chose the Postscript not HP install.

Problem was it did not recognize 2 sided documents and color was way to muted.

The white paper I consider the manual suggests theres a setting called pass through - int in the advanced tab if I recall in preferences ( they default to, and recommend pass through) if I am not mistaken this basically bypasses the RIP processing, it may be possible the postscript is converted at the workstation instead to the 600dpi output directly. Anyway bypassing but using default settings caused muted bland color settings. I therefore decided to try NOT passing through, using the RIP for conversion provided the typically good print I would expect, I also defaulted to Postscript Level 2 as I've had instances of Level 3 not working on the EFI XP12 RIP.

Another item one needs to do is go into the top Properties button when right clicking on the printer and then check out the many tabs. There is a Setup Options that defaults to Auto 2 way communication which is on, and another within the same tab area that allows one to turn on 2 sided printing if you have the duplex memory option as we do, but turning on Duplex only retains the setting if you turn OFF the auto 2 way communication. An additional tab within the setup options is defaulted to basic settings, this may be changed to a list of printers and the White paper link on about page 22 or 23 suggest a recommended setting for the Docucolor 12 as I guess it knows that the Doc 12 is not properly recognized at setup. I did try this and got all sorts of additional option to my printer including 200 through 600 dot line screens and stoastic - however with a couple changes to my print settings , the copier refused to print so I went back to Basic.

I will look into the above again, its likely that this works only with PASS Through set in Advanced Preferences so file is RIPPed at workstation while giving many color options it has the problem of having to learn a whole new list.

Good item of note.

The Xerox Universal Print Driver does in preferences let one save settings, by clicking on default in the preference menu a drop down list is presented and the option of adding more items so you can set for Color & Card, Color & Paper, Duplex etc.

It also has a tab in preferences for background copy - this may be its best equivilent to Free Form.

Anyway if you are running a 64 Bit operating system as I am then as far as I know this is the only driver for the Docucolor 12 because as far as I know EFI fiery has not provided any 64 bit driver for the Xerox Docucolor12

It may even be the best 64 bit driver in some cases for the Xerox 240, 242 as it allows multiple save setting like Color & Card, Color and Paper etc. Though in that case you can use the 64bit EFI Server Driver, but the EFI driver wrongly prints some backgrounds like screening on Microsoft Publisher files.


_________________________


Also available this driver meant for Mobile computers to set up printers on the fly but only Postscript printers

http://preview.tinyurl.com/l8m4eg


Supported Operating Systems and Environments
XP SP2 / Server 2003 32 Bit:
* Windows XP Home SP2, Windows XP Professional SP2, Windows Server
2003, Terminal Server, Citrix XP Server
Server 2003 64 Bit (for AMD & Intel Xeon processors (x64)):
* Windows XP Professional 64-Bit Edition, Windows Server 2003
64-Bit Edition
Vista 32 and 64 bit:
* Vista Home Basic, Vista Home Premium, Vista Business, Vista
Ultimate
Server 2008 32 and 64 bit:
* Server 2008 Standard, Server 2008 Enterprise, Server 2008 Data
Center


--
Ken Graham
CommunityPrinters.com
1020-103 ave.
Dawson Creek BC Canada
V1G 2G5

Tel. 250-782-7108

Sent from Linux computer -- see http://www.whylinuxisbetter.net

 

Just out of curiosity..

Did you try to create that outside Corel? Say like Paint that way you could compare both PS files and see the differences as they will be generated by different programs but same PS driver.

From my experience with Xerox drivers, you sould always use the dedicated one... Global and Mobile drivers are builted with a specific use in mind.

Regards

 

alright. so it seems that i found the problem and solved it. one needs a screwdriver, apart from postscript and unix knowledge to do so... but now it works as i want to i dont know if its perfectly alright to say so in this forum or cause any trouble to the owners. anyhow, thank you all for your advice and time and thoughts! ))

yes, there is nothing one can do OUTSIDE the machine, because there is SPECIFIC written code in it that FORBIDS the use of any other screening other what the manufacturer likes to sell. so, yes, they did write a piece of code that lowers the capabilities of it...

 

WOW - Now I'm Curious!!! can you mail me what you did???

 

Try and get a Fiery RIP to plug into the machine, that will resolve the issue. See if you can borrow one from a fellow printer and see how that goes.

 

Hi plus.ma

I have same issue. Could you please email me the solution?

 

There is many versions of firmware for this machine
New versions are better than old version.
Even scanning option whitout scanning board

 

wc 7655 printing resolution

My question is this link http://www.office.xerox.com/multifu...ifunction/workcentre-7655-7665-7675/enus.html say that printing resolution is 2400x2400, this http://www.office.xerox.com/latest/W65SS-01E.PDF say that postscript emulation 600x600dpi and 1200x1200 dpi, pcl is 600x600 dpi, which one is correct? and like plus.ma said,there is nothing we can do OUTSIDE the machine, because there is SPECIFIC written code in it that FORBIDS the use of any other screening other what the manufacturer likes to sell. so, yes, they did write a piece of code that lowers the capabilities of it..., anybody can tell me which code we need to change in order to print out 2400x2400 dpi?

 

Dear Plus.ma,

Can you please let me know what kind of hardware of software changements are needed to get your achievment with WC 7655?