On-Line/Off-Line Testing

On-Line/Off-Line Testing Based on the level of testing selected, on-line maintenance testing can assist in fault isolation by testing suspected equipment or systems with a mini- mum of interference with normal ship operation. If a suspected equipment or system checks out satis- factorily, then a possible source of the fault has been eliminated. This aids in the fault-isolation process. In general, the use of on-line testing provides a quick fault-isolation tool when you are trying to confirm equipment or system problems. When using on-line testing, you should be careful not to degrade the sys- tem or subsystem operational capability beyond the level specified by ship doctrine. Some combat systems equipment has the capa- bility of severing normal communications links and accepting preset or manual inputs when you are verifying system ability to correctly process data. This off-line testing offers a convenient method of iso- lating equipment or interface faults. As in on-line testing, care must be taken not to degrade the system or subsystem operational capabilities. One such off-line test is the system maintenance test (SMT) used in the Mk 86 gunfire control system (GFCS). The SMP is a computer program that enhances fictional testing and troubleshooting of the FCS. The SMP provides test conditions to check the integ- rity of input/output circuits to and from the computer and to check the fictional integrity of various functional systems. It is loaded into the FCS computer in place of the normal (tactical) FCS operational program. Therefore, the FCS is not functional in a tactical sense until the FCS operational computer program has been reloaded into the FCS computer fol- lowing the use of the SMP. The program includes a configuration entry routine, an executive routine, and approximately 60 individual tests that are organized into groups according to the interface channels between the computer and the peripheral units. Configuration entry allows the technician to adapt the program to a particular modification of the FCS. The executive routine provides the basic timing requirements for each test program and establishes testing priority in the event two or more tests are selected concurrently. The tests are grouped according to channel and unit numbers as follows: Channel 14 test programs are selected from units 1, 2, and 3. Channel 15 test programs are selected from unit 25. Channel 16 test programs are selected from unit 22. Channel 17 test programs are selected from unit 6. A sample of channel 14 test programs is shown in table 1-1. Notice that the tests selected at unit 2 or 3 are selected with a test number select code. The proce- dures for setting up these codes are in table 1-2. 1-8