Siemens SIPART DR20

SIPART DR20 Project Planning Manual
Fig. 5/16 TTY to remote system with SIPART bus and remote system isolated. Txd on the
remote system is an active current source that is not isolated from Rxd.
Fig. 5/17 TTY to remote system with the SIPART bus and the remote system isolated.
Txd on the remote system is an active current source isolated from Rxd.
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