MKS Stabil-Ion 370 Series, Инструкция по эксплуатации, Страница: 50 / 122

3 Installation
3-14
Series 370 Stabil-Ion Instruction Manual - 370119
The DTR line is set true by 370 on power up to indicate it is on line. When 370 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. 370 will continue to receive and buffer
characters until the terminator (LF) is received.
Upon receiving the terminator, 370 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 parsed
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. 370 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.
After transmitting the terminator, 370 will negate RTS and wait for the next incoming message.
To summarize:
CTS, DSR
Set the computer to indicate that 370 may output the next byte in its message. As shipped from
the factory these lines are forced “TRUE” by the switch settings of the 370 RS-232 printed
circuit board. Thus 370 will automatically assume the host is ready to receive. See Figure 2-13
on page 2-10 for the location of these switches.
DCD
Tested by 370 when a character is received. The character will be ignored unless DCD is
“TRUE”. As shipped from the factory, this line is forced “TRUE” by the switch settings.
DTR
Always asserted by 370. A “power ON” indication.
Table 3-4 RS-232 Connector Pin Assignments
Signal Pin Number Direction
Protective Ground 1 –
Transmitted Data 2 To Computer
Received Data 3 To 370
Request to Send (RTS) 4 To Computer
Clear to Send (DTS) 5 To 370
Data Set Ready (DSR) 6 To 370
Signal Ground (common return) 7 –
Data Carrier Detect (DCD) 8 To 370
Data Terminal Ready (DTR) 20 To Computer