3.11.1 BSC or Local Host Attached
On 3277s attached to a BSC or local host attached 3274, the coax path from the device to the control unit can be verified by means of the Test Request key. Pressing the Test Request key will cause the control unit to attempt to turn on the System Available indicator on the 3277. A Test Request message will also be generated if the control unit is online to the host.
3.11.2 SNA Attached
On 3277s attached to an SNA-configured 3274, the coax path from the device to the control unit can be verified by means of the Test Request key twice. The first pressing of the key will cause the control unit to attempt to turn off the Do Not Enter indicator; the second will cause the con-trol unit to attempt to turn on the System Available indi-cator. Operationally, this sequence is used to enter and exit 2-key sequence mode. Test Request followed by Clear is functionally equivalent to the Systems Request key on 3278s in SNA mode. Test Request followed by PA 1 is the equivalent in function to the ATTN key on 3278s in SNA mode. Test Request followed by Test Request returns the 3277 to normal operation.
Chapter 4. Subsystem Tests, External Tests, and Subsystem Service Aids
4.1 INTRODUCTION
Subsystem tests consist of the Bus and Lamp test and the IML tests.
4.2 INITIAL MACHINE LOAD (lML) TESTS
Initiating a normal 1M L (AL T switch not pressed and sys-tem diskette installed) invokes a sequence of hardware tests before operational code is loaded. When the 1M L pushbut-ton is pressed, a hardware Bus and Lamp test is performed.When the IML pushbutton is released, the diagnostic sequence begins and the error indications described in Figure 4-1 may be displayed.
Control Logic failure - All four indicators not lit indicates a control logic failure. The test sequence will not pro-ceed. The failure of any adapter can also cause this fail-ure. Parity problems can also appear to be control-logic failures.
Low Storage failure - A steady display of this code in the 8 4 2 1 indicators indicates a failure in low storage.
31SD failure - A flashing display of this code indicates the 3150 Diskette drive failed. A steady display of this code may be caused by any of the following:
• Failure of the 31SD Diskette drive to come "ready."
• A hung sequence (did not start) because of another adapter failure.
• Loss of ground to the 31SD Diskette drive (check A 1Z2 cable).
• Defective diskette.
Type A Adapter failure - A flashing display of this code indicates the test for this adapter not requiring a 3278 attached failed. A steady indication may indicate the sequence is hung (did not start!. Any activity from a device that would normally disable the adapter will also cause th is test to fail.
Type A Adapter Failure - A flashing display of this code indicates the tests for this adapter that require a 3278 attached failed. If a POR response was not detected from Port AO, this test will automatically be bypassed.
A failing display can also cause this test to fail.
Storage Card Failure - A flashing display of this code indicates the storage test failed. The failure could be caused by a defective storage card, failure of a compo-nent interfacing with storage (Extended Function Store feature), or incorrect customizing parameters. If a 3278 display is powered on at port AO, additional failure infor-mation will be displayed on the screen.
Figure 4·1. IML Test Error Indications
4.2.1 ALT 1 IML Mode
Pressing the IML pushbutton while holding the AL T switch in the AL T 1 position bypasses the normal 1M L test sequences .and causes the unit code to be directly loaded.
This will enable the user to bypass a failing test sequence (for example, a defective Type B adapter). In this case, the control unit is operational except for the Type B adapter.
The Bus and Lamp test functions the same as during a
Host Adapter Failure - A flashing display of this code indicates the host adapter/attachment test failed.
Failure could be caused by the following, in addition to defective cards: (1) model specified wrong when customized, (2) system diskette not for this machine, or (3) problem on the host interface has disabled the adapter.
Modem Wrap failure - A flashing display of this code indicates the Modem Wrap/DDSA test failed. The wrap test is run only if a wrappable modem was specified at customizing time. If a 3278 is powered on at port AO, additional information concerning the failure is available on the screen. Data displayed is as follows:
0111 016 - Modem failed to set Clear to Send 0111 013 - General modem failure
Type B Adapter failure - A flashing display of this code indicates the Type B Adapter test has failed. The test looks for the first Type B display powered on and attempts to do an Erase-Write-Erase operation. The cursor is left in the lower right portion of the screen.
Any Type B device failure that would disable the adapter would cause this test to fail.
1001 Encrypt/Decrypt Adapter Failure - A flashing display of this code indicates that the Encrypt/Decrypt Adapter test has failed.
1010 31SD Error - This flashing code is displayed whenever a 31SD problem has been detected after the initial 33FD test. This failure can also be caused by invalid tracks or data on the diskette.
Note: At least one complete IML test sequence is required to initialize control storage. Bypassing IML by using either AL T 1 or AL T 2 mode does not perform this initialization function; therefore it is possible that invalid parity may exist after initial power on if normallML has been bypassed.
Step Code Meaning
A hang condition at either step 3 or step 4 usually indicates a defec-tive system diskette or a configuration error.
Figure 4-2. AL T 1 IML Sequence
4.2.2 AL T 2 IML Mode, Models 51C and 52C with Wrappable Modem (Test/Operate Switch in Operate Position)
Pressing the IML pushbutton while holding the AL T switch in the AL T 2 position invokes an extended Modem Wrap test. Some types of modems require manual intervention to set up for wrap testing. The test checks the transmission path (Transmit and Receive Data lines) to and from the modem. Modem clocking is required to run this test success-fully, and a missing or defective modem clock will result in a failure indication (flashing 0111). The intent of this test is NOT to test the modem. The Bus and Lamp test functions
Begin Modem Wrap test
Communication Adapter Test running
Flashing - Communication Adapter Test failure Prewrap, Adapter Wrap, and Modem Wrap tests are running Flashing - Modem wrap test has failed.
Successful test - Carrier not present after completion of test.
Successful test - Carrier is pres-ent after completion of test.
Flashing - Modem wrap test has failed.
When this test is run in AL T 2 mode, the 3278 does not display the 842 1 indications.
Figure 4-3. ALT 2 IML Sequence, Models 51C and 52C with Wrappable Modem
4.2.3 AL T 2 IML Mode, Models 51C and 52C without Wrappable Modem (Test/Operate Switch in Test Position)
Pressing the IML pushbutton while holding the AL T switch in the AL T 2 position invokes an extended Modem Wrap test. When a nonwrappable modem is being used, the EIA test cable Test/Operate switch should be in the TEST position. This test checks the transmission path (Transmit and Receive Data lines) to and from the Test/Operate switch at the end of the cable. The test cable must be attached to the modem, and the modem must provide clocking or a failure indication of 0111 (flashing) will result. The Bus and Lamp test functions the same as during a normal 1M L. See Figure 4-4 for this AL T 2 sequence.
3. Wait 0110 Communication Adapter Test running
0110 Flashing -- Communication Adapter Test failure 4. Wait 0111 Prewrap, Adapter Wrap, and
Modem Wrap tests are running.
5. End Test 0111 Flashing - Modem Wrap test has failed.
1000 Successful test.
6. Return TEST! 1000 Carrier not present.
OPERATE switch 1111 Carrier is present.
to Operate para-graphs 5.4.3 and 5.4.4 of the 3274 MIM, for additional information on the Wrap Test without Modem, and DDS Adapter Wrap Test.
4.2.4 AL T 2 IML Mode, Modem Self Test for Model C with Greater than 1200-bps I ntegrated Modem
Pressing and holding the AL TIM L Address switch in posi-tion 2 will cause the modem self-test to be initiated and
repeated about every 4 seconds until the switch is released.
Releasing the switch should return the modem to Operate mode, regardless of the test results.
While the test is being run, the TEST light on the opera-tor panel is lit. If the test is successful, the Data Quality-Good indicator on the operator panel will flash each time the test is run. The indicators on the A 1 D2 card will also flash each time the test is run successfully.
If the test fails, the failing card is indicated in the A 1 D2 card indicators. Figures 4-5 through 4-7 show the meanings of the indicators. Cards indicated as failing are replaced in order of probability. If multiple A 1 D2 card indicators are displayed, replace all cards indicated.
Flashing Steady Operator Panel
Indicator Indicator Poor Indicator Failing Card
1111 Off Test successful
No failure
Figure 4-5. A 102 Card I ndicator for 2400-bps Integrated Modem
Flashing Steady Operator Panel
Indicator Indicator Poor Indicator Failing Card
1111 Off Test successful
No failure
1111 On or flashing 02,G2,F2,C4
0000 On or flashing 02, G2, C4 1111 On or flashing 02,F2,G2,C4
1000 On C2,G2,02
Poor Indicator Failing Card
Off Test successful
No failure
On or flashing E2,G2,F2,02,C4 On or flashing E2,G2,C2,C4 On or flashing E2,02,F2,G2,C4
On 02,F2,E2
On F2,02,E2,G2
On G2,E2,F2,02
On E2,F2,G2,02
On C2,G2,E2,02
Figure 4-7. A 102 Card I ndicator for 9600-bps Integrated Modem