Technical Support
Common Problems
This section of our website answers technical support questions that we face almost every day when we speak with our customers.
If you have a Technical Support problem that is not listed
here, please, please send us an email to:
COMMUNICATIONS BUFFER OVERFLOW
"Easytalk Copy Protection Device Not Installed" Message
EASYTALK PLUS CONFIGURATION TIPS
COMMUNICATIONS BUFFER OVERFLOW
Problem: The machine control receives programs with blocks of missing data. This normally results in buffer overflow errors to display. This problem is very common!
Possible Solutions: Verify that both the machine control and your DNC software configured for the same type of flow control, i.e., software, which is uses X-on/X-off (also known as DC1/DC3 and level 2 protocol), or Hardware, which utilizes the handshaking lines CTS/RTS (also known as level 1 protocol).
When your DNC software is configured to use the host computer's local serial ports (COM 1 or 2), it is important to disable the transmit and receive buffers for the computer's serial port hardware. Note that these buffers are only used on the 16550 series UART. If they are not disabled you may experience a buffer overflow problem on older controls.
Windows 95/NT can be configured to disable the transmit and receive (FIFO) buffers resulting in quicker response times to X-off commands. To configure your serial port accordingly go through the following steps:
Windows 95/98 Applications:
- Select My Computer
- Select Control Panel
- Select System
- Select Device Manager
- Select the appropriate COM port
- Select Port Settings
- Select Advanced
- Move the arrow on both the Receive and Transmit Buffer to LOW and click the option to disable the FIFO buffers.
- Select OK then exit back to the main screen.
Tests have shown that with this configuration a maximum of 2 characters are transmitted after a machine transmits an X-off character.
Changing the FIFO setting has become standard procedure for our technicians installing a DNC system on a computer running Windows and where we will be utilizing the built in COM 1 or COM 2 serial ports.
Windows NT Applications:
Beginning at the Start Menu, select the settings, Control Panel, and ports to display the individual port settings.
- Beginning at the Start Menu, select the settings, Control Panel, and ports to display the individual port settings.
- Highlight COM1 and click on the Advanced button.
- If the FIFO option is enabled simply click the selector to disable it.
COMMUNICATIONS INTERFERENCE
Problem: Intermittent communication problems as evidenced by corrupted and occasional missing data.
Possible Solutions: Interference with RS232 data can be introduced in many ways. Fortunately, careful selection, routing, and placement of the transmission cable can eliminate the most common factors.
The following list outlines the major considerations for avoiding data integrity problems caused by interference:
 | Make certain that all equipment is properly grounded. If uncertain on how to do this secure the services of a qualified electrician that has experience with industrial wiring. | ||||||
| Avoid routing cable in the vicinity of EMI generating equipment, such as: wire EDMs, arc welders, plasma cutters, large motors, fluorescent lights, etc. | ||||||
| Insure that the DNC computers and other peripherals hardware is equipped with AC surge protection devices. | ||||||
| Individual RS232 lines should be fitted with RS232 surge protectors. | ||||||
| Consider the use of Optical Isolators if problems persist | ||||||
| Select good quality cable that utilizes both a foil and braided shield. This cable is normally called low-capacitance or low-cap cable for short. | ||||||
| Follow any applicable wiring schematics or wiring diagrams:
| ||||||
| Avoid splicing cable, which breaks the continuity of the shield and introduces additional capacitance. | ||||||
| When confronted with extremely long cable runs (i.e.. over 200') consider the use of RS2323 to RS422 converters or s or short haul modems. | ||||||
| Another potential source of sporadic problems is radio transmitters. This is especially true in the vicinity of Amateur or CB transceivers when cable lengths approach multiples of a quarter wavelength of the operating frequency. | ||||||
| Independently verify that a CNC will indeed communicate via its RS232 port before assuming the DNC system is defective. | ||||||
| In areas of high intensity electrical fields, consider enclosing the cable within well-grounded electrical conduit. |
COMPUTER VIRUS
Computer Virus - A computer virus is usually defined as a self-replicating program that contains code that copies itself and that can "infect" other programs by modifying them or their environment in such a way that a call to an infected program implies a call to a possibly evolved copy of the virus. Computer viruses can cause entire hard disks or even computer networks to be corrupted. Sometimes the only cure is complete reformatting of the infected hard drives. Or a virus can just cause message or graphics to harmlessly appear.
A computer WORM is a self-contained program, or programs, that is able to spread functional copies of itself to other computer systems (usually via network connections). Unlike viruses, worms do not need to attach themselves to a host program to do damage. There are two basic types of worms--host computer worms and network worms.
NETWORK WORMS consist of multiple parts which are called "segments". Each segment can run on different machines, possibly doing different things. Network Worms use the network to send segments from one machine to another. Network worms that have one main segment which coordinates the work of the other segments are sometimes called an "octopus."
A TROJAN HORSE is a program that does something undocumented that the programmer intended, but that some users would not approve of if they knew about it. According to some people, a virus is a particular case of a Trojan Horse, namely one which is able to spread to other programs (i.e., it turns them into Trojans too). According to others, a virus that does not do any deliberate damage (other than merely replicating) is not a Trojan. Finally, despite the definitions, many people use the term "Trojan" to refer only to non-replicating virus, so that the set of Trojans and the set of viruses are disjoint.
This is just a basic overview of what viruses are. To avoid all problems associated with viruses, it is better to plan for their detections and elimination, rather then try to figures out what to do about a virus.
Our tips on how to stay virus-free:
| Obtain anti-virus and virus detection software. This can often be found in the same software package, but sometimes they are different packages. Update the software regularly. Maybe as often as once a week. |
| Back up all your important files on a regular basis, just is case you do get infected with a virus. |
| Never open an e-mail attachment that you aren't expecting, even if it is from someone you know and trust. The infamous "ILOVEYOU" virus was propagated from unsuspecting people sending e-mail to their friends and associates. This virus was reported to have caused billions of dollars of damage. |
| Never run an executable file (files with extension of EXE or COM) sent via e-mail or from an Internet news group. The "Happy.exe" virus is an example of this type of infection. |
| Never use floppy disks that you get from unknown sources. Make sure to check them with virus detection software before use. |
| If you use Microsoft Outlook as your e-mail program, verify that you have the latest updates. Also make sure that you have "Macro Virus Protection" turned on. |
EASYTALK SYSTEM REQUIREMENTS
CNC Engineering offers the following "Easytalk System Requirements:"
"EASYTALK is designed to run on 100% IBM compatible computers. No BIOS re-directs of resources or hardware address alterations for I/O ports are permissible.
REQUIRED HARDWARE/SOFTWARE:
| 80286 80486 (For DTE applications the computer should not exceed 486 class) |
| 1MB RAM |
| 3.5" 1.44 MB Floppy |
| 40 MB Hard Drive |
| 2 Serial Ports and 1 SPP Parallel Port (2 for GE 550 DTE replacements) |
| EGA or VGA Monitor |
| DOS 5.0 or higher |
NOTE: A Windows 95 DOS shell is unacceptable. Windows 95/98 computers must be booted directly to the Command prompt by pressing F8 during startup and selecting the Command Prompt Only option.
We can not guarantee compatibility with any TSR programs. Initial installation of EASYTALK must be performed with a "clean" system running DOS only. TSR programs may be loaded and tested after installation of EASYTALK."
NOTE: While CNC Engineering does not support running Easytalk Plus in Windows 95/98, Digitek Automation Systems has sold many copies of Easytalk Plus that have run does not support running Easytalk Plus in Windows 95/98, Digitek Automation Systems has sold many copies of Easytalk Plus that have run in Windows.
"Easytalk Copy Protection Device Not Installed" Message
Problem: Using the Green Security Lock (Activator) that comes with Easytalk Plus the screen displays a message "Easytalk Copy Protection Device Not Installed". Note that the Activator SIM is no longer shipped with current versions of the Focal*Point product from CNC Innovations.
The first thing to try is to add the following line to your AUTOEXEC.BAT file. This can also be typed from the DOS command line:
SET SSI_ACT=50,50,50
This usually fixes the problem.
If this is not successful then verify the following conditions when using the Rainbow/Activator SIM:
| Check the current BIOS setting for the computer's parallel port; oftentimes it must be configured as a Standard Parallel Port (SPP). |
| Make certain that all power saving modes in the computer's BIOS are not shutting off the parallel port. |
| Run the program SSIACT.EXE, located on the Easytalk Diagnostics disk, and use the recommended settings for adding a SET command in the Autoexec.bat file. For example, SET SSI_ACT=nn, nn, nn. If you do not have the SSIACT program use 50,50,50 for the "nn" variables. |
| Remove any TSR programs that could access the parallel port. |
| Verify that the printer port works by printing directly to a printer with the SIM removed. Also, some printers may need to be switched "ON" in order for the SIM to work, while others may have to be removed completely from the back of the SIM. In the later case, a simple work-around solution is to install a parallel switch box. |
| Test the SIM and printer port by running the remaining diagnostic programs on the diagnostics disk. |
| Some customers have found successful results by removing the SIM while the computer is booting and afterwards placing the module on the printer port. |
| If all else fails--and tests prove that the SIM will work on another computer--it may be necessary to add a second printer port to the problem computer. |
EASYTALK PLUS CONFIGURATION TIPS
Running in Windows 95/98
CNC Engineering does not support running Easytalk Plus in Windows 95/98. However, Digitek Automation Systems has sold many copies of Easytalk Plus that have run successfully in Windows. We've never had any problems. For those companies that want to run Easytalk in Windows CNC Engineering offers the following advice:
"Easytalk was developed in the 1980s for use on computers running an MS-DOS operating system. Furthermore, the program relies on hard-coded algorithms for a security module that predates today s high-speed computer parallel ports. CNC Engineering, Inc. does not sell or support Easytalk for operation on any Windows operating system. However, for our hundreds of customers that have been forced--due to changing technologies or software requirements--to migrate their Easytalk software to a Windows 95/98 or NT computer, we offer the following suggestions.
| Try running the program from the DOS Prompt and/or boot the computer in "Command Line Only" mode by pressing F8 when the computer displays the message Starting Windows 95. |
| Check the current BIOS setting for the computer s parallel port; oftentimes it must be configured as a Standard Parallel Port (SPP). Additionally, the Windows operating system may designate the same port as a high-speed port. If necessary, delete and reinstall the port as SPP using the Windows Device Manager, which is accessed by clicking the System icon located in the Control Panel. |
| Remove any. TSR programs that could access the parallel port, and make certain that all power saving modes in the computer s BIOS are not shutting off the parallel port. |
| Run the program SSIACT.EXE, located on the Diagnostics disk, and use the recommended settings for adding a SET environment variable in your Autoexec.bat file. If you do not have the SSIACT program try using SET 881_ACT5O, 50, 50. |
| Verify that the printer port works by printing directly to a printer with the SIM removed. Concerning printers, some may need to be switched "ON", while others may have to be completely disconnected in order for the SIM to work. In the later case, a simple work-around solution is to install a parallel switch box or add a second printer port. |
| Some customers have found successful results by removing the SIM while the computer is booting and afterwards placing the module on the printer port. |
| For those instances where Easytalk does work from within Windows, it is highly recommended that you run in full screen mode by setting the program s shortcut properties or by pressing Alt-Enter keyboard command after the program is running. |
| If all else fails--and tests prove that the SIM will work on another computer--it may be necessary to add a second printer port (LPT2) to the problem computer." |
EASYTALK NETWORK CAPABILITIES
CNC Engineering supports running Easytalk with standard local area networks: They offer the following information:
"EASYTALK systems can access and store data across standard network file servers. EASYTALK s data management sub-system uses standard DOS function calls for all its file activity. As such, any network operating system, which recognizes DOS functions calls should allow EASYTALK to operate smoothly. As a benchmark platform, EASYTALK is tested extensively on a Novell network before each software release."
It has been Digitek Automation's experience in the past that if a company has a network directory structure that has many levels, Easytalk's File Handler will not work properly. Keep directly names and levels short.
Also, mapping of drive letter can be confusing with Easytalk Plus. Contact Digitek for more information on networking and Easytalk.
Otherwise everything works well.
Grounding
In the UK they have earth and here in North America we have ground. They mean the same.
The main reason why grounding is used in today's electrical distribution networks is for safety. To accomplish this it is common practice to connect all the metallic parts in electrical equipment to an earth ground. The power company also connects its equipment to an earth ground. This earth ground is usually a series of metal rods driven deeply into the ground. These rods are connected to the power distribution network. Then if the insulation or connectors inside the equipment fails and a live wire touches the grounded metal case, there will be a short circuit. The short circuit will cause the fuse to immediately blow or circuit breaker to trip. When the fuse is blown or circuit breaker is tripped any dangerous voltages are disconnected. If this were not done, then the live wire could pass lethal current through a person touching the metal case. Or other equipment connected to the metal case could be damaged.
Grounding is also used to provide a for electricity consuming devices. If the grounding system that establishes this common point of reference is defective then there is no way to insure a common ground potential for the equipment connected. This often leads to ground potential differences and what are called ground loops. Ground loops frequently cause problems in computer networks, DNC systems and audio/video systems. These ground potential differences can be over 30 volts and can damage electronic circuits.
Therefore grounding systems used with machine tools have three main purposes:
| Over voltage protection: Lightning, line surges or unintentional contact with high voltage lines can cause dangerously high voltages to the electrical distribution system wires. Grounding provides an alternative path around the electrical system of homes and business to minimize damage from such occurrences. |
| Voltage stabilization: There are many sources of electricity in manufacturing facilities. Every transformer and electric distribution panel can be considered a separate source. If there were no a common reference point for all these voltage sources, then there would be no way to distribute the right voltage to each electricity consuming device. The earth is used as a common frame of reference because it is present just about every where. Consequently, many years ago when electrical distribution systems were being developed , earth ground became a nearly universal standard for all electric systems. |
| Alternative current path: in order to facilitate the operation of over current devices such as circuit breakers and fuses. This purpose of grounding is the key one to understand. Grounding systems provide a level of safety to humans and property in case of a malfunction of electrical equipment. |
This is a very basic overview of grounding as used in electrical distribution systems. Therefore if you are experiencing difficulty with your DNC system communicating with your machine tools make sure that the grounding system in your facility is properly installed. You may also want to consider driving grounding rods in to the ground for each machine tool.
Ground Loops
Problem: Improper grounding can create a lethal hazard plus it can interfere data transfer between a PC and CNC machine. Correct grounding is essential for the correct operation and safety of electrical and electronic equipment. Grounding can solve many problems, but it can also cause new ones. One of the most common problems is called a "ground loop". A ground loop occurs when two devices do not share the same source of ground. Since the ground signal sets a common frame of reference for data signals, a ground loop can inhibit or disrupt communications between devices. In addition, if the potential difference between the two devices exceeds 30 volts, expensive circuit damage is likely to occur.
Ground loops are the most common cause of AC line frequency hum in sound systems. You may have noticed this in your home audio system.
There is no absolute ground. There is always a certain amount of resistance to electrical currents between all grounding points. This resistance can change with environmental variables such as humidity, temperature, the type of connected equipment and many other variables. No matter how small, this resistance can always allow an electrical voltage to exist across it. The ground wires between wall sockets and power company transformers are not perfect conductors. If they were, ground loops would not be a problem.
Possible Solutions: The best ways to avoid problems caused by ground loops are:
- Make certain that all machine tool equipment, machine tool controls and computers, share the same ground source. The best source is earth ground through the use of grounding rods.
- For computer equipment and external AC powered peripheral hardware, never eliminate or by-pass the third wire ground lug on the AC power line cord.
- In very bad grounding environments, such as those arising from building to building communications, optical-isolators can be a cure. These inexpensive devices can protect equipment from surges as high as 2500 volts caused by improper grounding while maintaining the integrity of NC program data.
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Digitek Automation Systems, Inc.
Page was last modified:
08/26/2003 09:54:49 PM