Campbell Scientific CR1000KD CR800 and CR850 Measurement and Control Systems - Page 75

Section 5. System Overview One use of file encryption may be to secure proprietary code but make it available for copying. 5.1.10.5 Communications Encryption PakBus is the CR800 root communication protocol. By encrypting certain portions of PakBus communications, a high level of security is given to datalogger communications. See PakBus Encryption (p. 346) for more information. 5.1.10.6 Hiding Files The option to hide CRBasic program files provides a means, apart from or in conjunction with file encryption, of securing proprietary code, prevent it from being copied, or making it tamper resistant. .CR files, or files specified by the Include() instruction, can be hidden using the FileHide() instruction. The CR800 can locate and use hidden files on the fly, but a listing of the file or the file name are not available for viewing. See File Management (p. 324) for more information. 5.1.10.7 Signatures Recording and monitoring system and program signatures are important components of a security scheme. Read more about use of signatures in System Signatures (p. 150). 5.1.11 Maintenance Read More! See Maintenance (p. 397). With reasonable care, the CR800 should give many years of reliable service. 5.1.11.1 Protection from Water The CR800 and most of its peripherals must be protected from moisture. Moisture in the electronics will seriously damage, and probably render unrepairable, the CR800. Water can come from flooding or sprinkler irrigation, but most often comes as condensation. In most cases, protection from water is as easily accomplished as placing the CR800 in a weather-tight enclosure with desiccant and elevating the enclosure above the ground. The CR800 is shipped with desiccant to reduce humidity. Desiccant should be changed periodically. Do not completely seal the enclosure if lead acid batteries are present; hydrogen gas generated by the batteries may build up to an explosive concentration. Refer to Enclosures (p. 544) for information on available weather-tight enclosures. 5.1.11.2 Protection from Voltage Transients Read More! See Grounding (p. 86). The CR800 must be grounded to minimize the risk of damage by voltage transients associated with power surges and lightning-induced transients. Earth grounding is required to form a complete circuit for voltage-clamping devices internal to the CR800. Refer to the appendix Transient Voltage Suppressors for information on available surge-protection devices. 75