Frequently Asked Questions

• General Questions
• Media and Batteries
• IrDA
• Bluetooth™
• WLAN
• Printing (Fonts/Characters/Graphics)

General Questions

What printer size should I use?

The printer size you use is determined by the application and your company’s marketing orientation. Invoices are often larger while credit card receipts can use a smaller width. For more information, please click on either of the articles below:

Selecting a Portable Printer (DataTransmitter: Part 1, Part 2, Part 3)
Printer Size (Press Releases: January 20, 2008)

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How do I print a self-test?

To print a self-test, make sure the printer is turned off. Press and hold the Paper Feed Button and while holding the Paper Feed Button, press On/Off button. The current configuration of the printer will be printed.

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How Can I change Communication Printers Settings?

The printer can be set to IRDA, Serial, BT or Wi-Fi communication (check your printer configuration) through the dipswitches located in the battery compartment. Detailed settings information can be found in the printer’s users manual.

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How often should I clean the print head?

You may need to clean the print head and platen roller after printing a number of rolls of paper, whenever you load new supplies or when you see voids in the printout. We commend using the thermal print head cleaning pen (part number 757160).

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Where can I find the serial cable pin outs for Extech printers?

Download cable pinout diagram

Media and Batteries

How long does it take to charge the battery?

It takes approximately 180 minutes to charge the lithium-ion battery

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How long does the battery last?

Battery life is a function of environment, depth of use and number of charge/discharge cycles. The useful life of the battery is stated in terms of charge/discharge cycles. 300 cycles for the Extech Li-Ion battery pack. Extech batteries last 12–15 months in most operating environments. The cycle life may be reduced if daily depth of discharge is high and battery is operated at high ambient temperatures.

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How much can I print on one battery charge?

Battery Test Chart

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How do I know if I need a new battery?

A few of the indicators that you need a new battery:

• Light printing
• Declining charge capacity
• Increasing internal resistance
• Elevated self-discharge
• Premature voltage cut-off

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How do I store the batteries?

• Practice FIFO (First In First Out) inventory rotation
• Never store batteries under load
• Store batteries in a temperature-controlled environment

Storage parameters to achieve optimal battery capacity:

Cycle batteries with at least one Charge/Discharge cycle. Store batteries at 65% (+/-20%) humidity. Store batteries at 50% State of Charge

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What type of paper does Extech recommend in their thermal printers? Does the image last?

Our standard paper is a 15 year archival storage paper and is rated as “high” for environmental resistance. The grade is Kanzaki P390. Anything less will not hold up very well. For storage of P390, the temperature should be below 25c and RH below 70%. External resistance over the short term is higher than these. The paper is rated “Excellent” in it ability to hold an image after 15 hours in water.

IrDA

When I am using the Variable IrDA option on the 3750 together with an iPAQ device I need to reset the device after each receipt printed or otherwise I can not establish connection with the printer.

The reason why developers may experience this issue is the following: After negotiating the baud rate up to 34800 and completing the transmission of the receipt, the Extech printer follows the IrDA protocol guidelines and goes back to a 9600 baud rate. Some devices, however, do not fall back to the 9600Bps baud rate and stay at 38400 until the connection is closed. That is why if you are developing an application which will run on such a device you have two options:

1. Close the IrDA connection after each transmission and re-open the connection for the next receipt you wish to print, starting at 9600Bps baud rate.
2. Use the printer in its fixed baud rate mode where the baud rate will be fixed at 9600.

For short to medium text receipts it is recommended that you follow the second option since the faster baud rate will not make a big difference if printing text only.

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Do Extech Printers support communication with Pocket PC 2003 via infrared?

Sometimes baud rate might be the problem with some implementations of Pocket PC 2003 not handling lower rates correctly -- or at all. An example will be PPC2003 where the IR defaults to 115k baud which seems to be too fast for many IR printers. The problem is that some printers cannot begin the initial negotiation process at 115k baud. Extech printers are able to communicate via infrared with most devices. Occasional problems are reported when trying to communicate with Dell Axim via IrDa. Our IrDA stack developer (Actisys) and the IrDA protocol documents made it clear that the negotiation is supposed to start from the lowest baud rate (9600) up to whatever both devices support. Compaq had a similar issue after it moved to PocketPC2003. The following website has some helpful information.

http://support.dell.com/FileLib/Format.aspx?ReleaseID=R59395

Even though the version specified there is A00 the correct one is A05. The first time you try to go to the download site, it redirects to another page. You have to login, and provide a Dell product you are looking for support on. No other ID is needed for downloads, etc. After that's been entered, you should be able to paste and go straight to the "Release" link.

Bluetooth™

I am having problems trying to communicate with Bluetooth™

If you are having a problem establishing connection or communicating with the Extech printer through Bluetooth there are a few things which may be creating the problem:

• Make sure the printer is not too close to the host device
• Check if thee are any other devices which may interfere with the connection
• Make sure all appropriate BT software and drivers are installed on the host device
• Make sure the printer has all the correct DIP switch settings

There are several things that have to be considered when making an inquiry for a new Bluetooth device (Extech Printer). You have to make sure of the following:

• Is the Extech Printer discoverable? This is a setting in the printer.
• What profile is enable in the printer (SPP, DUN or LAP)
• Has the printer enabled the 'server' functionality?
• Has the Bluetooth name of the printer been changed?
• Does that unit of the printer work with any other Bluetooth enabled product (PC, Laptop, Mobile Phone, PDA)?
• Is security enabled on the printer?

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What are the default BT settings of Extech printers?

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What kind of a Bluetooth Security do the Extech Printers Support? Do we use any kind of encryption when we transfer MCR data?

While transferring the MCR information we rely directly on the Bluetooth interfaces security services by providing pin number and pairing support. Our Bluetooth interface follows the guidelines set by Bluetooth SIG Security Expert Group. The detailed spec link can be found at the following URL:

http://bluetooth.com/Bluetooth/Technology/Works/Security/

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How do I pair an Extech printer with a BT device (Authentication Protocol)?

Extech’s 2500 and 3750 printers support pairing. The BT pairing procedure establishes a secret key that is used in all future connections to authenticate device identity and encrypt data. Follow the instructions below to perform the pairing. Before beginning make sure that the all BT specifications have been set properly, including baud rate, DIP switch settings, parity, etc. Also, it is best that the commands are not sent directly but rather files are created and the files are sending. Before beginning the pairing the desired PIN number should be saved in the printer. Please click on the link below for detailed instructions.

Bluetooth Pairing Instructions

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Printer is resetting when trying to print in BT mode.

• If that happens, check the power LED.
• If the LED is purple then the reset is due to a low battery.
• Charge the battery (either internally or externally) and continue normal operation.
• If the LED is Blue - contact Extech’s Tech support.

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How many bits does the BT module support for encryption?

Bluetooth supports 128 Bit encryption

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When trying to connect to a BT Serial Port from a PC (WIN 2000/WIN XP) a message box appears requiring a BT PIN code. What is that code?

The code for Bluetooth is "0" or "1234". This is required when you set your Bluetooth security settings on your Notebook to High. If you lower the security level you should not be required to enter the pin code.

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Why can I not discover any services on the Extech printer when communicating via BT using my Psion Teklogix WorkAbout PRO?

The reason why you are experiencing problems while using the WorkAbout PRO with BT is that the BT modules of both devices are set to MASTER which prevents them from establishing communication. In order to resolve the issue you need to set the BT module inside the printer to behave as SLAVE. Instructions on how to do that are available by e-mailing Extech.

WLAN

What are the default 802.11g settings of Extech printers?

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When printing via 802.11 the last portion of my receipt gets "Cut Off".

When transferring data via the 802.11 interface in some occasions the last packet that is sent is still transmitting while the application and Windows have already closed the 802.11 link. As a result, the last portion of the receipt ends up being "Cut Off".

To avoid this:

• Always send the Esc C command in your application (more details on the command are available in the Developer’s Manual).
• Send the command AFTER you have sent all of the receipt data and make sure that in your application you keep the 802.11 connection OPEN until you receive the Cancel Request message back from the printer.
• This will guarantee that the entire receipt has been transferred and it is safe to close the 802.11 connection.
• Another thing that could solve the issue is sending extra NULL packets at the end of a receipt – each packet is about 1024 bytes. This way even if the last couple of packets get lost, no data will be missing from the receipt.
• Further 802.11b/g information is available on the Developer’s CD or upon request from Extech.

Printing (Fonts/Characters/Graphics)

How do I send a captured signature to the printer?

Sending a captured signature is the same as sending any 8-bit or compressed graphic. A signature can also be treated as a logo and be downloaded to one of the memory locations of the specific printer. (See question creating and saving logos.)

8- Bit Dot addressable Graphic Commands
8-Bit Compressed Graphic Commands

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How do I create and save logos into the printer?

Graphic Images can be stored in the form of a logo. This allows the printer to store them in memory locations and print them as needed. Different printers support different number of logos. Check the Developers manual for details. Single Byte Command is used to select a specific logo location.

One of the most common problems with logos is that the file is too big and as a result only part of it gets stored in memory. To prevent that, make sure that the correct printer is selected before you start designing the logo.

WordPad (Microsoft Word or Notepad are not suitable) should be used to design logos. From Page Setup select the appropriate printer. After the logo is designed, the best way is to print it to a .prn file. Open the file in DOS/ EDIT mode. Make sure to specify BINARY before you open the file. Go to the beginning of the file and delete all the characters up to the ESC V characters. Then insert the following command. ESC LG 0. Move the cursor to the end of the file and delete the LF character at the end. Insert the following commands ESC L G [255] ESC L g 0. Save the file and send it to the printer. The logo you have designed will be saved in location 0 of the printer.

If the logo you have designed is too big only part of it will get printed. In this case, go back to WordPad and resize the image and repeat all the steps.

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Can Bar Code Printing be left or right justified? Or does it always print in the middle of the paper?

The bar code printing function currently does not support right or left justification. Bar Codes are always printed in the middle of the page.

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I'm trying to print a large file. When the file is larger than 35k the printer starts printing illegible characters.

The problem above can be experienced if you specify no flow control while you are transmitting the information you need to print. The incoming buffer in the Extech Printers is 32K large. For files less than 32K the flow control should not make a difference. However, it is a good programming practice if you always specify either hardware or software flow control while transferring data to the printer.

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Why am I having problems printing characters from the extended tables in the printer?

Often problems can arise while trying to print characters from the extended character tables in the printer. The cause might not be the printer but the specific communication software that is being used. Thus for example if Terra Term is used the characters print out differently from what is expected. In cases like that what is recommended is using the DOS editor to create a text file (It will not work if Notepad or WordPAd is used.) All that the test file has to contain is the character or characters which have to be printed. Save the file. Then using Terra Term send the text file to the printer and this time the characters should come out right. This is a test which can be performed to diagnose if the problem is in the printer or in the communication program being used.

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How do I download characters and fonts to the extended character tables?

The Extech 3750THS printer provides to the user the ability to replace the factory-installed fonts. This allows the 3750THS to adapt to many application specific character sets. Use the EXTECH_FONT EDIT application located on the Developer’s CD to create the specific font. Then use Asm2bdf to convert the file to a .BDF format and use Bdftodwn to convert the .BDF to a printer friendly format. The last two applications can also be found on the Developer’s CD. After these conversions have been done the new font is ready to be downloaded. Click on the link for instructions on downloading new fonts.

Instructions to download new fonts

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Is it possible to print text or graphics in two columns?

If you are printing in text mode then the printer can only print one column. If you are in graphics mode and using the Extech Graphics driver or PrinterCE to print from a Windows application ( For Ex. WordPad), you can format your text in 2 columns. If you are sending the information directly to the Serial Port using your own application then you will have to map the information from before and send one line at a time. What we mean is this:

For Example if you need to print the following list:

You will have to save the information before you can send it to the printer. And you have to save it in the following order

1.Green ... 3.Yellow first and this will be your first line
and then
2.Blue ... 4.Red and this will be your second line.

The application that you are using will have to save the information before hand in this format and this will create the illusion that it is in two columns but the way the printer actually works is printing one full line at a time.

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How do I make applications designed for hand held devices print on the Extech Printer?

In order to be able to print from a hand held device to an Extech Printer a third party software is necessary. For Windows CE, Pocket PC or Windows Mobile operative systems, visit www.fieldsoftware.com

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The Printer gets hot and stops printing and it does not start printing until after it cools down.

As a preventive feature, the print head on the Extech printer will stop printing when its temperature gets too high. It will not start printing again until the printer has cooled down. That is why it is recommended that the printer is not left exposed to direct sunlight or in proximity to hot objects such as a car motor etc. Refer to the Users Manual for complete maintenance information.

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After finishing the print job the printer sends a few hex characters to the host application.

There is a special section in the Developer’s Manual which deals with control characters. One of them is the EOT character which the printer sends back to the host device when the buffer is empty. The reason you are getting more than one character is probably that the Buffer is emptied more than once during the transmission. Every time that happens the printer transmits an EOT character. Developers should just ignore these characters.