Polycom ViewStation EX4000 - Manual (Page 116)

Integrators’ Reference Manual for ViewStation EX, ViewStation FX, and VS4000
106 www.polycom.com
Both endpoints in Pass-Thru Mode —Two stations set to Pass-Thru
Mode behave as a null-modem between their respective externally
connected devices. Data from the RS-232 port on one endpoint is
pushed through the call to the other endpoint, and then transmitted
to the endpoint’s RS-232 port. The data channel speed is
dynamically allocated. The maximum data flow rate is based on the
bandwidth of the call.
Because data throughput has priority over video throughput, video
bandwidth may be restricted to support data requirements. Audio
is not compromised.
Far-site endpoint in Control Mode —If the near site is set to
Pass-Thru Mode and the far site is set to Control Mode, the far-site
device acts as a slave under the control of the device connected to
the near-site endpoint’s RS-232 port.
The following table summarizes the port operation based on the
RS-232 mode configured by each endpoint.
Flow Control
The ViewStation EX, ViewStation FX, and VS4000 support
hardware flow control. Users should make sure that hardware flow
control settings are consistent between the system and the external
devices on both sides of the connection.
Table 5-2. RS-232 Control and Pass-Thru Modes
Near-Side Mode Far-Side Mode Resulting Operation
Control N/A Near-side CLI
(Command Line
Interface)
Pass-Thru Control The near-side controls
the CLI of the far side
Pass-Thru Pass-Thru The data is passed in
full-duplex mode from
the near-side RS-232
port to the far-side
RS-232 port