$00ff H-Bridge driver test fixture HW:0191 FW:0194.00.00 $0010nnnn[cr] Start test, run nnnn cycles (Hex) !0010a[cr] (0000 runs continuously) $0020[cr] Report cycle count !0020,nnnnnnnnn[cr] Cycle count (Decimal) $0021[cr] Clear cycle count !0021a[cr] $0030[cr] Report test parameters (Hex) !0030,tttt,cccc,aa,bb,xx,yy[cr] tttt: Stop threshold cccc: Stop count aa: Right leg on, mS bb: off, mS xx: Left leg on, mS yy: off, mS $0031ttttccccaabbxxyy[cr] Set test parameters (Hex) !0031a[cr] tttt: Stop threshold cccc: Stop count aa: Right leg on, mS bb: off, mS xx: Left leg on, mS yy: off, mS !0040ccccccaaaxxx[cr] Cycle test stats (Hex) cccccc Cycle count aaa Leg a-b current xxx Leg x-y current The 'Right leg' cycle is the left high and the right low, i.e. ADC measuring current at the right side of the bridge to ground and the 'Left leg' cycle is conversely the right high and the left low: For the DB9-M, this is pins 2-/7+ and 2+/7- respectively. Leg current can be calculated from: Iout = ((ADC/1023)*2.5)/Rlow. The stop threshold is the ADC reading considered to be an open bridge and the stop count is the number of times (Non-consecutive) the ADC reading falls below that threshold after which the test is terminated. The stop threshold can range from 0 to 9999 (1023 to 9999 is STOP!) and the stop count can range from 1 to 9999. The test times are in mS, but are actually 1.024mS because of the way time is counted in the PIC. A setting of '10' will result in and actual time of 10.24mS. Minimum on time is 1mS, minimum off time is 0mS. Note that 5mS is the minimum integration time where current is read at the end of the on cycle and shorter times will result in inaccurate ADC readings. Faster integration can be acheived by reducing the value of R9 and R10. The maximum on and off times are 99mS. The left button (Facing the test connector) starts testing when pressed for 2 or more seconds. The right button stops a test in progress immediately and when idle clears the test count after 5 seconds. Pressing both buttons displays the timing parameters for 5 seconds and then displays the threshold and count limits until either button is released. During testing, data is transmitted to RS232 and displayed in HEX (to save time) but after testing has stopped and during parameter display, values are shown in decimal. Any RS232 command received during testing will stop the testing immediately. DSUB9-M connector pin out: 1 Right-leg High When not testing, pots may be read at H-to-M and M-to-L 2 Right-leg Middle for the purpose of setting the bridge current. Just be 3 Right-leg Low sure to remove any UUT when setting the pots. ---------------- 6 Left-leg High 7 Left-leg Middle 8 Left-leg Low ---------------- 4 Ground 9 Left (Start) button, active low with no ESD protection 5 Right (Stop/Reset) button, active low with no ESD protection Capture this menu to file if the terminal scroll back buffer makes it hard to read the top of the menu!