Experimental Physics and
Industrial Control System

Marty Kraimer <[email protected]> · Tue, 09 Sep 2003 13:11:01 -0500

The only thing base(<type>) does is determine how a field is converted from an
integer to a string by dbStaticRun, i.e. how dbGetStringNum convert the number.
In the 3.12 versions of epics the old DCT used base to decide how to convert
from an integer to a string. In 3.12 DCT did not keep numberic fields as strings
and base was very important. Starting with 3.13 it lost most of its meaning
since dbStaticNoRun keeps numeric fields as strings. We should have removed this
attribute from the recordtype definitions. Perhaps Andrew will remove it for 3.15?
Note that numeric fields in record dbd files are converted during ioc
initialization by strtol or strtoul with a third argument of 0. This means that
the string is interpeted as a decimal, octal (leading 0), or hex (leading 0x) value.
Marty Kraimer

J. Frederick Bartlett wrote:

  The field definition for an EPICS database record allows for the
specification of a base radix with the syntax:
 base(<base-type>)
where <base-type> can be DECIMAL or HEX with DECIMAL the default, c.f.
"EPICS IOC Application Developer's Guide"; Release 3.14beta1; page 67-68.
  I would interpret this to mean that any numeric value assigned to this
field when defining an instance of an EPICS record would be interpreted
according to the designated (or default) base radix. This does not, however,
appear to be the case.
 Here is a field definition from a .dbd file:
          field(BADR,DBF_ULONG) {
                prompt("VME base address (hex)")
                promptgroup(GUI_DISPLAY)
                base(HEX)
                interest(1)
                initial("0")
          }
and here is an instance of a record definition in a .db file:
          record(vme,"TRG_CSEQ_M001/NXTA:R") {
                field(DESC, "CSEQ Next Address Read")
                field(SCAN, "Passive")
                field(BADR, "400000")
                field(ADDR, "0x8000")
                field(AMOD, "A24")
                field(DSIZ, "D16")
                field(RDWT, "Read")
                field(NMAX, "2048")
                field(NUSE, "1113")
                field(AINC, "2")
                field(ASND, "1")
                field(EXPR, "0")}
The value that appears in the BADR field is decimal 400000. If the value is
prefixed by "0x", i.e. "0x400000", the field value is hexadecimal 400000.
 Am I missing something?
 Fritz Bartlett

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System