Rockwell Automation 2708-DH5B2L_DH5B4L Attended Workstation - Manual (Page 57)

Chapter 5
Configuration Menus
5–16
To make an RS-232 loopback plug, use a 9-pin female D connector.
Jumper pin 2 to 3 (TxD to RxD)
Jumper pin 7 to 8 (RTS to CTS)
Jumper pin 6 to 4 (DSR to DTR)
In addition, Data Carrier Detect (DCD) must be high.
To make an RS-422 loopback plug, use a 9-pin female D connector.
Jumper pin 3 to 2 (TxD + to RxD +) through a 1K ohm resistor
Jumper pin 1 to 4 (RxD– to TxD–) through a 1K ohm resistor
The 1,000 ohm resistor is placed in-line between each Receive and Transmit
pin to simulate a 1,000 ft. length of cable.
Install the loopback connector into the communications port of the
workstation BEFORE starting this test.
Once this test is started, the upper line of the display should show the
transmit pattern flashing past. If a character is lost, then the display will
freeze. This indicates a test failure. If a character is substituted, a beep will
sound and the display will pause for 3 seconds. Losing characters is
indicative of a hardware error occurring in the unit.
The keys 1 through 9, <ENTER>, <CLEAR>, <RIGHT ARROW>, <IN>
and <OUT> will be transmitted to the comm line.
Pressing <EXIT> will terminate the test and display 8–Comm Loopback
Test.
Note: This test will not operate on a workstation which is currently set up as
a Submaster, Alternate Submaster or Concentrator. This test CANNOT be
selected from the comm line.
This test can also be used for remote loopback through a modem for
checking the integrity of a modem line. In this case, character substitution
errors may occur occasionally.
8–Aux Comm Transmit Test
When Enter is pressed while 8–Aux Comm Transmit Test is showing on the
display, the following prompt appears on the display:
DTR: ON CD: ON
DTR cannot be toggled OFF.
Menu 6: Diagnostics
Menu Parameters (cont’d)