On Friday, November 06, 2015 10:30 AM, Ian Abbott wrote:
> On 05/11/15 19:03, Hartley Sweeten wrote:
>> On Thursday, November 05, 2015 5:43 AM, Ian Abbott wrote:
>>> On 04/11/15 16:55, H Hartley Sweeten wrote:
>>>> The analog outputs can use an external reference to create the D/A output
>>>> range. Add an entry to the comedi_lrange table for it and modify the
>>>> (*insn_write) to support it.
>>>>
>>>> Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
>>>> Cc: Ian Abbott <abbotti@xxxxxxxxx>
>>>> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>>>> ---
>>>> drivers/staging/comedi/drivers/adv_pci1710.c | 13 ++++++++-----
>>>> 1 file changed, 8 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/staging/comedi/drivers/adv_pci1710.c b/drivers/staging/comedi/drivers/adv_pci1710.c
>>>> index 86ed288..339130b 100644
>>>> --- a/drivers/staging/comedi/drivers/adv_pci1710.c
>>>> +++ b/drivers/staging/comedi/drivers/adv_pci1710.c
>>>> @@ -65,6 +65,8 @@
>>>> #define PCI171X_CLRFIFO_REG 0x09 /* W: clear FIFO */
>>>> #define PCI171X_DA_REG(x) (0x0a + ((x) * 2)) /* W: D/A register */
>>>> #define PCI171X_DAREF_REG 0x0e /* W: D/A reference control */
>>>> +#define PCI171X_DAREF(c, r) (((r) & 0x3) << ((c) * 2))
>>>> +#define PCI171X_DAREF_MASK(c) PCI171X_DAREF((c), 0x3)
>>>> #define PCI171X_DI_REG 0x10 /* R: digital inputs */
>>>> #define PCI171X_DO_REG 0x10 /* W: digital outputs */
>>>> #define PCI171X_TIMER_BASE 0x18 /* R/W: 8254 timer */
>>>> @@ -111,9 +113,10 @@ static const struct comedi_lrange pci1711_ai_range = {
>>>> };
>>>>
>>>> static const struct comedi_lrange pci171x_ao_range = {
>>>> - 2, {
>>>> - UNI_RANGE(5),
>>>> - UNI_RANGE(10)
>>>> + 3, {
>>>> + UNI_RANGE(5), /* internal -5V ref */
>>>> + UNI_RANGE(10), /* internal -10V ref */
>>>> + RANGE_ext(0, 1) /* external Vref (+/-10V max) */
>>>
>>> Minor niggle:
>>>
>>> The comment for the external Vref is slightly confusing. The manual I
>>> have says:
>>>
>>> By inputting an external reference voltage: -xV , where |x| <= 10,
>>> you will get a output voltage range: 0 to xV.
>>>
>>> So the external reference voltage is never positive. How about this?:
>> >
>>> /* external -xV ref, |x| <= 10 */
>>
>> Again it appears we have different manuals.
>
> Indeed!
Ian,
The link you referenced for the manual in another email also has this manual:
http://downloadt.advantech.com/ProductFile/Downloadfile1/1-11P65IR/PCI-1710U.pdf
It does not include the register map but has this information about the analog
outputs:
Page 26:
The maximum reference input voltage is +/-10V and maximum output scaling
Is +/-10V.
Page 32:
Output Range Using External Reference 0 ~ +xV @ -xV (-10 <= x <= 10)
Based on that, are you ok with the RANGE_ext(0,1) option?
Thanks,
Hartley
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