ifm
System Manual
ecomat
mobile
PDM360NG (CR1080, CR1081, CR9042) Target V01
2011-07-28
Glossary of Terms
450
Master
Handles the complete organisation on the bus.
The master decides on the bus access time
and polls the
slaves cyclically.
Mission time TM
Mission time T
M
is the period of time covering
the intended use of an SRP/CS.
Misuse
The use of a product in a way not intended by
the designer.
The manufacturer of the product has to warn
against readily predictable misuse in his user
information.
MMI
HMI =
H
uman
M
achine
I
nterface
HMI
(
→
page
Monitoring
Safety function which ensures that a protective
measure is initiated:
if the ability of a component or an element
to perform its function is diminished.
if the process conditions are changed in
such a way that the resulting risk
increases.
MRAM
MRAM means
M
agnetoresistive
R
andom
A
ccess
M
emory. The information is stored by
means of magnetic storage elements. The
property of certain materials is used to change
their electrical resistance when exposed to
magnetic fields.
Advantages of MRAM as compared to
conventional RAM memories:
non volatile (like FRAM), but:
access time only approx. 35 ns,
unlimited number of access cycles
possible.
MSB
M
ost
S
ignificant
B
it/Byte
MTBF
M
ean
T
ime
B
etween
F
ailures (MTBF)
Is the expected value of the operating time
between two consecutive failures of items that
are maintained.
NOTE: For items that are NOT maintained the
mean life
MTTF is the expected value (mean
value) of the distribution of lives.
MTTF
M
ean
T
ime
T
o
F
ailure (MTTF) or: mean life.
MTTFd
M
ean
T
ime
T
o
d
angerous
F
ailure = the
expectation of the mean time to dangerous
failure.
Designation
Range
low
3 years < MTTF
d
< 10 years
medium
10 years < MTTF
d
< 30 years
high
30 years < MTTF
d
< 100 years
Table: Mean time of each channel to the dangerous failure
MTTF
d
Muting
Muting is the temporary automatic suspension
of a safety function(s) by the SRP/CS.
Example: The safety light curtain is bridged, if
the closing tools have reached a finger-proof
distance to each other. The operator can now
approach the machine without any danger and
guide the workpiece.
N
NMT
NMT =
N
etwork
M
anagemen
t
= (here: in the
CAN bus)
The NMT master controls the operating states
of the NMT slaves.