Siemens SIMATIC ET 200AL - Page 933

Glossary
Communication
Function Manual, 12/2017, A5E03735815-AF
247
Device
Generic term for:
● Automation systems (PLC, PC, for example)
● Distributed I/O systems
● Field devices (for example, PLC, PC, hydraulic devices, pneumatic devices) and
● Active network components (for example, switches, routers)
● Gateways to PROFIBUS, AS interface or other fieldbus systems
Device certificates
Such certificates are signed by a certificate authority (CA).
The signature of an end-entity certificate is checked with the public key of the certificate
authority certificate.
The "Subject" attribute must not be identical to the "Issuer" attribute.
The "Subject", for example, contains the name of a program as with the OPC UA application
certificate.
"Issuer" is the certificate authority that signed the certificate.
The "CA" field must be set to "False".
DP master
Within PROFIBUS DP, a master in the distributed I/O that behaves according to the EN
50170 standard, Part 3.
→
See also DP slave
DP slave
Slave in the distributed I/O that is operated on PROFIBUS with the PROFIBUS DP protocol
and behaves according to the EN 50170 standard, Part 3.
→
See also DP master
Duplex
Data transmission system; a distinction is made between full and half duplex.
Half duplex: One channel is available for alternate data exchange (sending or receiving
alternately but not at the same time).
Full duplex: Two channels are available for simultaneous data exchange in both directions
(simultaneous sending and receiving in both directions).
End-entity certificate
→ See also device certificate