Campbell Scientific CR1000 Measurement and Control System - Manual (Page 466)

Section 11. Glossary
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single‐ended
Denotes a sensor or measurement terminal wherein the analog voltage
signal is carried on a single lead, which is measured with respect to
ground.
skipped scans
Occurs when the CR1000 program is too long for the scan interval.
Skipped scans can cause errors in pulse measurements.
slow sequence
A usually slower secondary scan in the CR1000 CRBasic program. The
main scan has priority over a slow sequence.
SMTP
Simple Mail Transfer Protocol. A TCP/IP application protocol.
SNP
Snapshot file
SP
Space
state
Whether a device is on or off.