TM-9-1200-215-34&P Technical Manual for M109 Automatic Fire Control System (AFCS) Download
Page 38 of 266
TM 9–1200–215–34&P 2–3 Section IV – MANUAL TROUBLESHOOTING Page Page General 2–3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Functional Description 2–3 . . . . . . . . . . . . . . . . . . . . . . . . Post–Maintenance Test 2–6 . . . . . . . . . . . . . . . . . . . . . . . 2–8. GENERAL This chapter contains information on checks and corrective actions required to isolate defects in the AFCS Computer Unit (ACU) and correct the defects by means of maintenance. The manual troubleshooting shall begin with a fault or symptom and lead to a single fault isolation of the problem. In cases where the maintenance must be performed at a higher level, the description will note “Forward ACU to Depot”. 2–9. FUNCTIONAL DESCRIPTION a. The AFCS Computer Unit (ACU) receives vehicle position data from the on–board positioning system for ballistic computation and weapons control and calculates distance and direction to the target location entered from the Display Unit (DU). Using stored ballistics data, the ACU calculates appropriate gun tube elevation to reach the target. Elevation and azimuth commands are sent to the weapon’s hydraulics system to adjust gun tube direction and elevation. The ACU automatically performs radio interface functions for the system. It controls radios, radio network interface, intercom interface, and composition/decomposition of messages. It is the digital processing device for the DU, interfaces with the on–board vehicle positioning system, and contains the embedded trainer controller for simulating navigation and gun laying missions. POWER CONDITIONING UNIT VIS TTS AZ TACH EL TACH AZ SERVO VALVE EL SERVO VALVE MODE SELECTOR VALVE DISPLAY UNIT DYNAMIC REFERENCE UNIT VMS MODEM PDIU MVS SERVO CONTROLLER/ INTERFACE CCA DISCRETE INTERFACE CCA POWER SUPPLY MIL–STD–1553 INTERFACE CCA HYD CNTRLR RELAY SINGLE– BOARD COMPUTER CCA SCSI PORT ETHERNET PORT VGA PORT SERIAL I/O PORT KEYBOARD/MOUSE/FLAT PANEL DISPLAY PORT TCIM CCA IDE HARD DRIVE ACU SINCGARS ISA BUS Figure 2–1. AFCS Computer Unit Block Diagram