MKS Granville-Phillips 358 series, Instruction Manual

Page: 65 / 122

Installation
Series 358 Micro-Ion Controller Instruction Manual - 358013 - Rev. B
65
Sy
stem C
o
mponents
Ini
tial
Setup
Installation
Before You
Begin
4.15 Connecting the RS-232
Computer Interface
Handshake Lines
For instructions for setting up this interface, see RS-232 Computer Interface
Setup on page 37.
The DTR line is set true on power up to indicate it is on line. When the
controller receives a start bit on the received data line it will input and buffer
a character. The DCD line must be true at the time each character is
received or that character will be ignored. The controller will continue to
receive and buffer characters until the terminator (LF) is received.
Upon receiving the terminator, the controller will assert the RTS line as a
holdoff, to prevent the host computer from attempting to transmit further
data until the message just received has been decoded and a reply has been
output.
During output of the reply, the incoming handshake lines CTS, and DSR are
tested prior to beginning transmission of each character. The controller will
wait until both are true before beginning transmission of a character, and
will not test them again until ready to begin transmitting the next character.
After transmitting the terminator, the controller will negate RTS and wait for
the next incoming message.
Figure 4-10 Controller Rear Panel with RS-232 Option