Remote Control Of The Lcr Meter; Using The Interfaces; Rs232 Interface; The Rs232 Interface Standard - Protek 9216A User Manual

Chapter
3

Remote Control of the LCR Meter

Remote Programming Reference
The 9216A LCR meter may be controlled and programmed remotely using either an
RS232 Any computer supporting either of these interfaces may be used with the 9216A.
Both interfaces are simultaneously active and are accessed via the connectors on the
rear panel. The 9216A responds to commands from either interface and returns answers
to the interface from which the command came. All front and rear panel features (except
power) may be controlled.

Using the Interfaces

RS232 Interface

The RS232 interface specifies how to transfer data between a data terminal equipment
(DTE), such as a computer, and a data communications equipment (DCE), such as a
modem. The interface includes two signal lines that can be used for half-duplex (one-
way) or full duplex (simultaneous two-way) operation. Additional lines are used for con-
trolling the flow of the data in the sense that data cannot be transferred unless the
appropriate flow control line is first asserted (changed from 0 to 1).

The RS232 Interface Standard

The RS232 interface specifies a 9-pin connector as the interface in data communications
networks—a 9-pin D-SUB male connector at the DTE (data terminal equipment) and a 9-
pin D-SUB female connector at the DCE (data communications equipment)—with the
pins designated as shown in Table 3-1.
The most common RS232 signals are the following:
Request to Send (RTS) and Clear to Send (CTS): The RTS signal line is asserted by the

computer to inform the modem that it wants to transmit data. If the modem decides that it
is read to receive data, it will assert the CTS line. Typically, once the computer asserts
RTS, it will wait for the modem to assert CTS before transmitting data.
 Data Terminal Ready (DTR) and Data Set Ready (DSR): This line is asserted by the
computer to inform the modem that it is ready to receive data. In response, the modem
will assert DSR to indicate that it is turned on.
 Data Carrier Detect (DCD): This control line is asserted by the modem, informing the
computer that it has established a physical connection to another modem and is ready to
transfer data.
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