AMETEK CW Series Programming Manual - Manual (Page 16)

Programming Manual 4-1
SECTION 4
RS-232 INTERFACE
This section describes how to connect the CW-P for remote programming with a
controller using the RS232 interface. The RS-232 interface provides a simpler 3-wire
serial interface (compared to the GPIB parallel interface), while fully supporting the
SCPI commands presented in Section 3.
4.1 RS-232 Interface Operation
The CW-P uses a 3-wire connection to the controller: TxD, transmit data; RxD, receive
data; GND, signal ground. When connecting the CW-P, appropriate consideration is
required to ensure that the TxD line of the CW-P connects to the RxD line of the
controller and the RxD line of the CW-P connects to the TxD line of the controller. See
Section 4.3.
The CW-P implements the XON/XOFF (Transmit On/Transmit Off) software protocol to
control the flow of data between it and the controller.
Under this protocol, the receiver
(either the CW-P or the controller) controls when data is sent, and requests that the
transmitter (controller or CW-P) stop sending data, if necessary. To enable data flow,
the receiver sends an XON (ASCII 19) on its TxD line to the transmitter. To request
that data flow be stopped, the receiver sends an XOFF (ASCII 17) to the transmitter.
4.2 RS-232 Characteristics
The interface characteristics are listed below:
Baud Rate: 9600
Data Bits: 8
Stop Bits: 1
Parity: None
Protocol: XON/XOFF