comparison: content/hp34970a_3.rst
content/hp34970a_3.rst
- changeset 130
- 56ffb9577050
- parent 128
- aba381b2bac9
equal
deleted
inserted
replaced
| 129:42a19a0d1c99 | 130:56ffb9577050 |
|---|---|
| 2 HP 34970A Data Acquisition Unit - part 3 | 2 HP 34970A Data Acquisition Unit - part 3 |
| 3 ========================================== | 3 ========================================== |
| 4 | 4 |
| 5 :Author: David Douard | 5 :Author: David Douard |
| 6 :Category: Electronics | 6 :Category: Electronics |
| 7 :Tags: HP, 34970A, DMM, repair, test equipment | 7 :Tags: HP, 34970A, HP34970A, DMM, repair, test equipment |
| 8 :series: HP 34970A repair | 8 :series: HP 34970A repair |
| 9 :series_index: 3 | 9 :series_index: 3 |
| 10 | 10 |
| 11 | 11 |
| 12 As explained in `the previous post in this series <{filename}/hp34970a_2.rst>`_, | 12 As explained in `the previous post in this series <{filename}/hp34970a_2.rst>`_, |
| 15 display managed by an arduino or similar. | 15 display managed by an arduino or similar. |
| 16 | 16 |
| 17 Protocol | 17 Protocol |
| 18 ======== | 18 ======== |
| 19 | 19 |
| 20 The serial communication takes place at a rather unusual speed: 187.5 | 20 The serial communication takes place at a rather unusual speed: 187500 bit/s, |
| 21 kbits/s, otherwise, a standard 8N1 scheme. | 21 otherwise, a 8E1 scheme (with even parity bit). |
| 22 | 22 |
| 23 The protocol consist in a transmission frame with a start of | 23 The protocol consist in a transmission frame with a start of |
| 24 transmission handcheck, some commands with arguments, and an end of | 24 transmission handcheck, some commands with arguments, and an end of |
| 25 transmission packet. | 25 transmission packet. |
| 26 | 26 |
| 73 --------------- | 73 --------------- |
| 74 | 74 |
| 75 The indicator flags are always sent as 4 bytes, each bit controlling | 75 The indicator flags are always sent as 4 bytes, each bit controlling |
| 76 one indicator. | 76 one indicator. |
| 77 | 77 |
| 78 The indicator flags I've been able to identify so far | 78 The indicator flags I've been able to identify so far are below (please see |
| 79 are below. | 79 `this page <{filename}/hp34970a_protocol.rst>`_ for the complete protocol |
| 80 description). | |
| 80 | 81 |
| 81 Let's say the frame is: ``<0x0A> <0x04> <F1> <F2> <F3> <F4>``, then: | 82 Let's say the frame is: ``<0x0A> <0x04> <F1> <F2> <F3> <F4>``, then: |
| 82 | 83 |
| 83 | 84 |
| 84 - F1.8 = | 85 - F1.8 = |
