The Mule: Quickstart guide
This guide provides sufficient details for most uses to get The Mule up and running in the shortest possible time. For more detailed information including full technical specifications and advanced configuration details visit The Mule web site...
The Mule converts RS232 ASCII data into scancodes which the computer interprets as keystrokes. It can act as a 'virtual keyboard' by emulating a keyboard directly in hardware (KeyWedge Mode) or can utilise the USB port to achieve similar results utilising the Human Interface Driver (HID) provided with many modern operating systems.
The Mule can be used to simplify the interconnection of devices such as Barcode Scanners, Weighing Scales and other technical instrumentation to applications software even if the software authors had not anticipated the need for such interoperability.
The Mule can be used to allow one computer to control another. This has wide application in industrial, technical, scientific, manufacturing and testing environments.
Fitting the interface cablePush the connector into the square hole in The Mule. Press firmly until the latch engages (listen for a slight click) and the cable cannot be pulled out again.
Removing the interface cableRelieve the tension on the latch by pushing the cable firmly inward towards The Mule. To release the latch insert a straightened paper clip (or similar tool) into the small hole in the base of The Mule beneath the cable. The cable can then be easily withdrawn.
Green Lamp: Ready
The green lamp is lit when The Mule has powered up correctly and is waiting for RS232 data to arrive. The lamp is extinguished during the period it is unable to accept further data while it is transmitting to the KeyWedge or USB cables.
Red Lamp: Overload
The Mule continuously monitors the voltage of the power drawn from the PC. If The Mule is configured to power the RS232 device from the computer the Overload Lamp will light if the computer cannot provide sufficient power (a brief indication when the computer powers up is normal). If this happens you should reconfigure the links inside The Mule and the RS232 device to use an external power source. Further details about advanced configuration options for The Mule can be found on our web site.
Connecting The Mule
The Mule can be fitted with either of two cable types: KeyWedge and USB. KeyWedge works with any computer using a IBM compatible Keyboard. It does not need software drivers and can work with any operating system such as MSDOS which may not have USB drivers.
Some computers, particularly laptops, do not have an external connector for a keyboard. The USB option can be used provided the computer operating system supports the USB port with a HID (Human Interface Device) driver. Many recent operating systems provide this support- MS Windows, MAC, Linux, Sun, HP Unix for example.
Both KeyWedge and USB interfaces send data which the computer interprets as keystrokes.
External Power connector
The Mule is usually powered from power drawn from the host computer. A connector is provided if it is necessary to use an external power supply unit to power a device connected to The Mule. For further details about this optional facility see the full technical details on our web site.
Device power source
Pins 4 and 9 are interconnected inside The Mule. Either may be used to source power to drive an external RS232 device. These pins have been chosen to be compatible with the normal DTR function of pin 4.
In its default configuration pins 4 and 9 are connected to a voltage regulator inside The Mule. If a unregulated voltage (9-12v) is applied to the External Power connector a regulated 5 volt source will appear at pins 4 and 9. 300mA can be drawn continuously and up to 1A for short intermittent periods.
If you intend to use this optional feature more technical detail can be found on the web site.
RS232 data format
The default data format is: 9600 baud, 8 data bits, no parity, 1 Stop bit.
It is recommended that The Mule be operated with a proper RTS/CTS handshake. This will ensure no data loss or transmission problems.
Missing characters, double characters, incorrect characters, unusual symbols appearing on the screen, computer lockup or beeping sounds from the computer all indicate a handshaking problem.
If the incoming data stream conforms to all of the constraints listed below The Mule may be operated successfully without a handshake.
Full details on RS232 handshaking options for The Mule can be found on the web site.
Help and Support
Detailed operations, up to date technical information, lists of scancodes and more can be found on our web site.
If you have a question not answered by the web site or you need help then please contact the support desk by emailing from the web site.
Keywedge and The Mule are trademarks owned by Altek Instruments Ltd UK. © 2004
The Mule is a low powered digital device and in normal circumstances is unlikely to cause any significant radio (or any other) interference. The following statements are made in order to comply with legislation in relevant jurisdictions.