Performing The Initial Diagnostic Checkout; Performing The Loopback Diagnostic Test - Siemens MJ-4 Series Installation Manual

6.1 Performing the Initial Diagnostic Checkout

Prior to performing these tests, become familiar with operating and configuring the MJ-4 Control Panel. See the
MJ-4A & MJ-4B Voltage Regulator Control Panel Installation and Operations Manual (Siemens manual no. 21-
115527-023).
1. On the MJ-4 Control Panel, under the < DIAGNOSTICS > menu, go to the "CM Test?:" screen.
2. Press the Change key and toggle from "OFF" to "INTERN," and then press the Save key. (If the password is
requested, enter the password as described in the note below and proceed.) The "CM Test:?" screen should
display "INTERN" for several seconds before changing to "OFF." If the display does not change to "OFF,"
then check the physical installation of the communications module before proceeding.
Note: When you try to change the "CM Test?:" value, the MJ-4 Control Panel may request that the password be
entered. If the default passwords are in effect, then the password for the Diagnostics menu is "3333." For more
information refer to the MJ-4A & MJ-4B Installation and Operations Manual.
3. Once the "CM Test?:" screen value has returned to "OFF," press the down arrow key to display the next data
item, "CM TestStat." This screen indicates the status of the Communications Module test. The possible test
value results are shown below. A value of xxx2 (where x may be 0-9 or a-f), indicates that the test passed.
A value of xxx0 or xxx1indicates a failure. (Note that in firmware versions of 2.xx (e.g., 2.13, 2.44, etc) xxx3
indicates the test passed and xxx2 indicates an internal problem.)
•
xxx0 indicates the test did not run at all. Run the test again, allowing extra time for the communications
module to power up. This should take about 15 seconds. The Watchdog LED will blink after the module
successfully completes self test and initialization.
•
xxx1 indicates an internal problem with the MJ-4 Communications Module. Contact Siemens for
assistance.

6.2 Performing the Loopback Diagnostic Test

The loopback test evaluates the MJ-4 for communications readiness. For this test, connect the transmit output to the
receive input of the communications module. When testing the fiber optic interface, ensure that the cable used meets
the requirements outlined in section 7.1. When testing the RS-232/485 interface, only the RS-232 portion of the
circuit can be tested by connecting a wire from the transmit pin (Txd) to the receive pin (Rxd) of the screw terminal
block connector.
1. To Perform the Loopback Test on the Fiber Optic Interface, ensure that the Jumper J14 is in the 1-2 position.
2. Scroll to the "CM Test?:" data item in the <DIAGNOSTICS> menu on the MJ-4 Control Panel display.
3. Press the Change key, then the up arrow key to select "LOOPBK." If the password is requested, enter the
password and proceed.
4. Press the Save key. "LOOPBK" will display for several seconds before changing automatically to "OFF." If
this does not occur, then recheck the physical installation of the communications module and retry.
5. Once the "CM Test?:" screen displays "OFF," press the down arrow key to display the "CM TestStat" data
item. This screen gives the status of the communications module test. A value of xxx6 (where x may be 0-9 or
a-f), indicates that the loopback test passed. A value of xxx0 – xxx5 indicates a failure. (Note that in
firmware versions of 2.xx (e.g., 2.13, 2.44, etc) xxx7 indicates the test passed, xxx3 indicates failure, and xxx6
is a communication problem.)
•
xxx0 indicates the test did not run at all. Run the test again, allowing extra time for the communications
module to power up. This should take about 15 seconds. The Watchdog LED will blink after the module
successfully completes self test and initialization.
•
xxx1 indicates an internal problem with the MJ-4 Communications Module. Contact Siemens for
assistance.
•
xxx2 indicates the loopback test failed. Check the loopback connectors and repeat the test.
MJ-4 Communications Module
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