HBM AED9101D - Diagnostic Bus Connection

AED9101D
I3563-1.0 en 25
termination with commands STR1;TDD1; in the relevant
AED. If the DIP switch for bus termination is set to OFF,
the commands will not take effect, i.e. bus termination
will remain switched off!
Important
Termination resistors must only be activated at the end
points of the interface cable. If resistors are also activ
ated in between, this will weaken the signal and anything
from interference to data transmission failure could res
ult.
RS485 with a 2wire connection
Wiring and bus termination occur in the same way in the
2‐wire connection with RS‐485; it is merely lines RA and
RB that are missing. Their function is taken up by lines
TA and TB. Line TA/RA is also described as T/R and line
TB/RB as T/R+.
6.5 Connecting the diagnostic bus
The diagnostic bus is used for analysis during the devel-
opment of a measuring system and the encrypted
exchange of data in a legal-for-trade configuration with
digital indicator DWS2103. The bus is designed as a
2-wire bus with RS-485 (lines: TA/RA, TB/RB and GND).