Motorola MSXX07 Application Notes

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Cable Adapters

•Female 25 pin D, TxD on pin 2, p/n 50-12100-378

•Female 25 pin D, TxD on pin 3, p/n 50-12100-377

•Male 25 pin D, TxD on pin 2, p/n 50-12100-380

•Male 25 pin D, TxD on pin 3, p/n 50-12100-379

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Optional Accessories

•Push button trigger cable, p/n 25-04950-01R

•Photo sensor trigger cable, p/n 25-13176-01R (retroreflective, IR 850 nm, 7 foot range)

•Fixed-mount stand, p/n 20-60136-01R

•Mounting bracket, p/n KT-65578-01R

Application Notes

Standard RS-232 voltage levels typically range between +12V and -12V to ensure adequate noise rejection over

long distances. Devices which support TTL level RS-232 signaling typically drive signals between 0V and +5V.

Extensive testing has shown that TTL levels are interpreted correctly by the majority of standard RS-232 hosts over

cable distances of six feet or less, even in extreme conditions.

Multi-interface Miniscan products fall into the TTL RS-232 device category. All standard RS-232 cables available

from Motorola for the Miniscan family measure six feet or less, and should not present a problem. If a particular

host does not support TTL levels, a separate conversion cable is available (25-62186-xx) which contains

electronics to adapt the TTL levels of a multi-interface Miniscan into standard RS-232 levels.

The Universal Serial Bus provides a smart plug-and-play interface for easy integration. In USB communication, the

root hub located on the host controls all traffic. USB hosts in general react poorly in certain harsh environments

compared to traditional host interfaces such as RS-232. These environments include areas with high ESD levels or

situations in which the system is subject to Electrical Fast Transients (EFT).

Typical symptoms of these environments are:

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Frequent scanner resets

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Scanner occasionally loses power (due to host initiated shutdown)

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Occasional host lockups.

Because multi-interface Miniscan products are often exposed to these environments due to the nature of scanner

placement, they have been safeguarded as much as possible to prevent physical damage. Despite design

precautions, testing shows that some USB hosts cannot tolerate these environments. In this case, try placing a

self-powered USB hub close to the host, between the scanner and host, as a buffer to the host against the harsh

environment. This may not be a valid solution in all cases.