RE: streamdevice mbbiDirect mask

[Mark Rivers <rivers@cars.uchicago.edu>]

Ø  If I want to mask it with a value 0xC1(b"1100,0001"), how to set NOBT/SHFT field?

 

My understanding is that you cannot do that.  I think the NOBT and SHFT fields are designed to allow you to set a contiguous set of bits to 1 in MASK.  It does not allow a mask with arbitrary locations of 1’s and 0’s.

 

The standard asyn device support does support longin records with an arbitrary mask.

 

Mark

 

 

From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-bounces@aps.anl.gov] On Behalf Of Silver
Sent: Saturday, July 18, 2015 11:25 PM
To: tech-talk
Subject: streamdevice mbbiDirect mask

 

hi,

 

in the website of streamdevice, it says:

Normal Operation

Depending on the format type, different record fields are used for output and input. The variable x stands for the written or read value.

DOUBLE format (e.g. %f):

Not allowed.

LONG format (e.g. %i):

If MASK==0 (because NOBT is not set):

Output: x=VAL
Input: VAL=x

If MASK!=0:

Output: x=RVAL&MASK
Input: RVAL=x&MASK

MASK is initialized to NOBT 1-bits shifted left by SHFT.

ENUM format (e.g. %{):

Not allowed.

STRING format (e.g. %s):

Not allowed.

 

In my case, I use mbbiDirect and get a value as 0x29 (b"0010,1001") in VAL field. If I want to mask it with a value 0xC1(b"1100,0001"), how to set NOBT/SHFT field?

Thanks a lot in advance.

 

 

 

 

---

Best wishes

Geyang 2015-07-19