B-3
ET 200U Distributed I/O Station
EWA 4NEB 812 6087–02b
ET 200
Bus for connecting the distributed I/O to the S5–115U ... S5–155U
programmable controllers or any other adequate master. The ET 200 is
characterized by fast response times since only small data volumes
(bytes) are transferred.
The ET 200 is based on the PROFIBUS standard (DIN 19245/part 1)
and the PROFIBUS–DP draft standard (DIN E 19245/Part 3).
The ET 200 operates according to the master–slave principle. The
IM 308–B master interface module or any host incorporating the
CP 5480–DP can be master.
The ET 200B, ET 200C or ET 200U distributed I/O systems can be
configured as slaves. Distributed I/O systems including an SPM mo-
dule can also be connected.
Event
An important message which the ET 200U(DP Standard/FMS), for
example, sends to the FMS master.
F
Field devices
All devices outside the switchgear room installed in the field, i.e.
where the sensors and actuators are.
Floating
In floating I/O modules, the reference potentials of the control and
load circuits are electrically isolated, e.g. via optical couplers, relay
contacts or line transformers. Input and output circuits can be grouped.
Do not confuse with “isolated”.
FMS
Fieldbus Message Specification,
³
DIN 19245, Part 2.
FMS service
FMS services are used by the FMS master to process the
“ET 200U(FMS)” object.
There are FMS services which require acknowledgement and those
which need not be acknowledged. For an FMS service requiring ac-
knowledgement (e.g. MSAZ), the ET 200U(DP Standard/FMS) ac-
knowledges the receipt of an FMS service to the FMS master. If an
FMS service need not be acknowledged (e.g. multicast and broadcast),
the ET 200U(DP Standard/FMS) sends no acknowledgement to the
FMS master.
FMS master
The term FMS master defines a master acting in accordance with the
PROFIBUS standard, DIN 19245, Parts 1 and 2.
FMS slave
The term FMS slave defines a slave acting in accordance with the
PROFIBUS standard, DIN 19245, Parts 1 and 2.
FREEZE
is a
³
control command.
Using this control command, the DP master can “freeze” the input
statuses to their actual value. The input data are updated again only
when the DP master once more sends the FREEZE control command.
I
Indication
An indication is used to mark a request (.ind).
Inherently short–circuit
proof
Equipment is inherently short–circuit proof if a short–circuit is not
likely to occur under certain operating conditions if suitable measures
are taken.
Insulation monitoring
Circuit for monitoring the insulation resistance of a plant.
I/O bus
Bus which links the I/O modules to the CPU or IM 308–B interface
module.
Glossary