DNF Controls Analyst, RS422/RS232 Tester - Manual (Page 28)

MONITOR Mode Troubleshooting Tips
Step# On Analyst Display What it means
1 The top line of the display,
after
ÎÎ, is blank.
There is no communication from the Controller.
Press the [DIR] key to select the DIR
ÎÎ screen.
Press the [RxTx] key to swap the transmit and
receive lines from the Controller. If characters are
now displayed on the top line of the display, the
transmit and receive lines are swapped.
IN Port RS232 Only-
The DTR indicator and RTS indicator on the front of
the Analyst will turn on when the DTR and RTS signal
lines are “ON”.
Press the [RTS] key to connect IN port RTS to CTS,
and IN port DTR to DSR. Some controllers require a
CTS and/or DSR handshake line to enable their
transmitter.
2 The top line of the display,
after
ÎÎ, shows
unreadable characters.
The Controller is transmitting data to the Analyst, but
the transmit circuit may be reversed.
Press the [DIR] key to select the DIR
ÎÎ screen.
Press the [Rx+] key to reverse the receive lines
(RS422 only) at the Analyst. If readable data is now
displayed on the top line of the display, the Controller
transmit lines are reversed.
Page 24 of 31 The Analyst RS422/RS232 Tester