Siemens 6SR41 series Product User Manual page 189

between the two devices. The use of a PC for downloading requires special serial
communications software to be available on the PC, which may link to the drive via RS232 or
through the Host Simulator via an ethernet connection.
DRCTRY
Directory file for system tokens and flags used in the compilation of system programs. It
provides a direct lookup table of ASCII names to internal ID numbers. It also identifies
whether the flag is a word or bit-field, and also whether it can be used as an input or output
only, or can be used for both.
Drive
The term "drive" refers to the power conversion equipment that converts utility power into
power for a motor in a controlled manner.
ELV
ELV is an acronym for extra low voltage, and represents any voltage not exceeding a limit
that is generally accepted to be 50 VAC and 120 VDC (ripple free).
EMC
EMC is an acronym for electromagnetic compatibility–the ability of equipment to function
satisfactorily in its electromagnetic environment without introducing intolerable
electromagnetic disturbances to anything in that environment.
ESD
ESD is an acronym for electrostatic discharge. ESD is an undesirable electrical side effect
that occurs when static charges build up on a surface and are discharged to another. When
printed circuit boards are involved, impaired operation and component damage are possible
side effects due to the static-sensitive nature of the PC board components. These side
effects may manifest themselves as intermittent problems or total component failures. It is
important to recognize that these effects are cumulative and may not be obvious.
Fault log
Fault messages are saved to memory so that the operator may view them at a later time.
This memory location is called the fault log. The fault log lists both fault and alarm
messages, the date and time that they occurred, and the time and date that they are reset.
Faults
Faults are error conditions that have occurred in the Perfect Harmony system. The severity
of faults vary. Likewise, the treatment or corrective action for a fault may vary from changing
a parameter value to replacing a hardware component such as a fuse.
Product User Manual
Operating Instructions, Version AE 12/2009, A5E01454341C
Glossary
187