Campbell Scientific CR1000KD CR800 and CR850 Measurement and Control Systems - Page 447

Section 11. Glossary UPS Uninterrubtable power supply. A UPS can be constructed for most datalogger applications using ac line power, an ac/ac or ac/dc wall adapter, a charge controller, and a rechargeable battery. User Program The CRBasic program written by the CR800 user in the CRBasic Editor or the Short Cut program generator. USR: A portion of CR800 memory dedicated to the storage of image or other files. URI uniform resource identifier URL uniform resource locater variable A packet of CR800 memory given an alphanumeric name, which holds a potentially changing number or string. Vac Volts alternating current. Also VAC. Mains or grid power is high‐level Vac, usually 110 Vac or 220 Vac at a fixed frequency of 50 Hz or 60 Hz. High‐level Vac is used as a primary power source for Campbell Scientific power supplies. Do not connect high‐level Vac directly to the CR800. The CR800 measures varying frequencies of low‐level Vac in the range of ±20 Vac. Vdc Volts direct current. Also VDC. The CR800 operates with a nominal 12‐ Vdc power supply. It can supply nominal 12 Vdc, regulated 5 Vdc, and variable excitation in the ±2.5 Vdc range. It measures analog voltage in the ±5.0‐Vdc range and pulse voltage in the ±20‐Vdc range. Volt meter An inexpensive and readily available device useful in troubleshooting data acquisition system faults. 447