Glossary
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
Glossary-5
DP master
A master which behaves in accordance with EN 50170, Part 3 is known as a DP master.
DP slave
A slave operated on PROFIBUS with PROFIBUS DP protocol and in accordance with EN
50170, Part 3 is referred to as DP slave.
DPV1
The designation DPV1 means extension of the functionality of the acyclical services (to
include new interrupts, for example) provided by the DP protocol. The DPV1 functionality has
been incorporated into IEC 61158/EN 50170, volume 2, PROFIBUS.
Electrically isolated
The reference potential of the control and on-load power circuits of isolated I/O modules is
electrically isolated; for example, by optocouplers, relay contact or transformer. I/O circuits
can be interconnected with a root circuit.
Equipotential bonding
Electrical connection (equipotential bonding conductor) which eliminates potential difference
between electrical equipment and external conductive bodies by drawing potential to the
same or near the same level, in order to prevent disturbing or dangerous voltages between
these bodies.
Error display
One of the possible reactions of the operating system to a runtime error is to output an error
message. Further reactions: Error reaction in the user program, CPU in STOP.
Error handling via OB
After the operating system has detected a specific error (e.g. access error with STEP 7), it
calls a dedicated block (Error OB) that determines further CPU actions.
Error response
Reaction to a runtime error. Reactions of the operating system: It sets the automation
system to STOP, indicates the error, or calls an OB in which the user can program a
reaction.
ERTEC
See ASIC