[Emc-commit] emc2/docs/src/hal drivers.lyx,1.15,1.16

[Jeff E. <cv...@cv...>]

Modified file emc2/docs/src/hal/drivers.lyx

Full file:
<http://cvs.linuxcnc.org/cvs/emc2/docs/src/hal/drivers.lyx?rev=1.16>

Difference:
<http://cvs.linuxcnc.org/cvs/emc2/docs/src/hal/drivers.lyx.diff?r1=1.15;r2=1.16>

Branch: TRUNK

Log:
revision 1.16
date: 2007/06/29 12:24:29;  author: jepler;  state: Exp;  lines: +8 -7
* watchdog timer tristates pluto outputs after 6.5ms without communication from PC
* quadrature encoder improvements: up to 8191 counts per polling cycle, no limit on counts per revolution when index pulse is used
* fix several 'bugs' which caused too many chip resources to be used

--- drivers.lyx	2007/06/26 03:01:14	1.15
+++ drivers.lyx	2007/06/29 12:24:29	1.16
@@ -4856,7 +4856,6 @@
  The counters operate in "4x" mode.
  The maximum useful quadrature rate is 8191 counts per emc2 servo cycle,
  or about 8MHz for EMC2's default 1ms servo rate.
- An axis with index pulse must have fewer than 8192 counts per revolution.
 \layout Itemize
 
 4 PWM channels, "up/down" or "pwm+dir" style.
@@ -5821,9 +5820,11 @@
 \end_inset 
 
  max).
- However, software bugs in the pluto_servo firmware or emc2, or a crash
- of the computer where emc2 is running, can leave the Pluto-P pins in an
- undefined state.
+ If the watchdog timer is enabled (the default), these pins are also tristated
+ after an interruption of communication between emc2 and the board.
+ The watchdog timer takes approximately 6.5ms to activate.
+ However, software bugs in the pluto_servo firmware or emc2 can leave the
+ Pluto-P pins in an undefined state.
 \layout Itemize
 
 In pwm+dir mode, by default dir is HIGH for negative values and LOW for
@@ -5835,10 +5836,10 @@
 The index input is triggered on the rising edge.
  Initial testing has shown that the QZx inputs are particularly noise sensitive,
  due to being polled every 25ns.
- Digital filtering has been added to filter pulses shorter than 150ns (six
+ Digital filtering has been added to filter pulses shorter than 175ns (seven
  polling times).
- Additional external filtering, such as a Schmitt buffer or inverter, RC
- filter, or differential receiver (if applicable) is recommended.
+ Additional external filtering on all input pins, such as a Schmitt buffer
+ or inverter, RC filter, or differential receiver (if applicable) is recommended.
 \layout Itemize
 
 The IN1\SpecialChar \ldots{}