NB: This manual documents a 20+ year old version of EPICS, see here for the EPICS 7 Record Reference documentation.
EPICS Record Reference Manual
scan parameters
read parameters
operator display parameters
monitor parameters
run-time and simulation mode parameters
Soft Channel
device support module can be specified in the DTYP field. For a list of other device support modules currently supported at the user's local site, use the dbst
utility in R3.13. The ULIM and LLIM fields determine the usable range of signal values. Any value of SGNL below LLIM or above ULIM is outside the range and will not be stored in the array. In the NELM field the user must specify the array size, e.g., the number of array elements. Each element in the NELM field holds the counts for an interval of the range of signal counts, the range specified by ULIM and LLIM. These intervals are determined by dividing the range by NELM:
(ULIM - LLIM) / NELM.
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
SVL | Signal Value Location (an input link) | INLINK | Yes | 0 | No | No | N/A | No |
SGNL | Signal Value | DOUBLE | No | 0 | Yes | Yes | Yes | No |
DTYP | Device Type | DEVCHOICE | Yes | 0 | Yes | No | No | |
NELM | Number of elements in array | USHORT | Yes | 1 | Yes | No | No | No |
ULIM | Upper Signal Limit | DOUBLE | Yes | 0 | Yes | Yes | No | No |
LLIM | Lower Signal Limit | DOUBLE | Yes | 0 | Yes | Yes | No | No |
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
NAME | Record Name | STRING [29] | Yes | 0 | Yes | No | No | |
DESC | Description | STRING [29] | Yes | Null | Yes | Yes | No | No |
If SDEL is greater than 0, it causes a callback routine to be called. The number specified in SDEL is the callback routines interval. The callback routine is called every SDEL seconds. The callback routine posts an event if MCNT is greater than 0.
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
MDEL | Monitor Delta | SHORT | Yes | 0 | Yes | Yes | No | No |
SDEL | Monitor Seconds Deadband | FLOAT | Yes | 0 | Yes | No | No | No |
The BPTR field contains a pointer to the unsigned long array of frequency values. The VAL field references this array as well. However, the BPTR field is not accessible at run-time.
The MCNT field keeps counts the number of signal counts since the last monitor was invoked.
The WDOG field contains a pointer to the callback control structure and is of no interest to the user.
The collections controls field (CMD) is a menu field with five choices: Read
, Clear
, Start
, Stop
, and Setup
. When Read
, the record retrieves its values and adds them to the signal array. This command will first clear the signal counts which have already been read when it is first invoked. The Clear
command erases the signal counts, setting the elements in the array back to zero. Afterwards, the field is set back to Read
. The Start
command simply causes the record to read signal values into the array. Unlike Read
, it doesn't clear the array first. The Stop
command disables the reading of signal values into the array. The Setup
command waits until the start
or read
command has been issued to start counting.
The CSTA or collections status field implements the CMD field choices by enabling or disabling the reading of values into the histogram array. While FALSE, no signals are added to the array. While TRUE, signals are read and added to the array. The field is initialized to TRUE. The Stop
command is the only command that sets CSTA to FALSE. On the other hand, the Start
command is the only command that sets it to TRUE. Thus, Start
must be invoked after each Stop
command in order to enable counting; invoking Read
will not enable signal counting after Stop
has been invoked.
A typical use of these fields would be to initialize the CMD field to Read
(it is initialized to this command by default), to use the Stop
command to disable counting when necessary, after which the Start
command can be invoked to re-start the signal count.
The WDTH field is a private field that holds the signal width of the array elements. For instance, if the LLIM was configured to be 4.0 and ULIM was configured to be 12.0 and the NELM was set to 4, then the WDTH for each array would be 2. Thus, it is (ULIM - LLIM) / NELM.
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
BPTR | Buffer Pointer | NOACCESS | No | 0 | No | No | No | No |
VAL | Value Field | See BPTR | No | 0 | Yes | No | No | No |
MCNT | Monitor Counts | SHORT | No | 0 | Yes | No | No | No |
WDOG | Watchdog Callback | NOACCESS | No | 0 | No | No | No | No |
CMD | Collections Control | RECCHOICE | No | 0 | Yes | Yes | No | No |
CSTA | Collections Status | SHORT | No | 1 | Yes | No | No | No |
WDTH | Element Width | DOUBLE | No | 0 | Yes | No | No | No |
The following fields are used to operate the histogram record in simulation mode. See Chapter 3, Fields Common to Many Record Types, for more information on the simulation mode fields.
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
SIOL | Simulation Value Location | INLINK | Yes | 0 | No | No | N/A | No |
SVAL | Simulation Value | DOUBLE | No | 0 | Yes | Yes | No | No |
SIML | Simulation Mode Location | INLINK | Yes | 0 | No | No | N/A | No |
SIMM | Simulation Mode | GBLCHOICE | No | 0 | Yes | Yes | No | No |
SIMS | Simulation Mode Alarm Severity | GBLCHOICE | Yes | 0 | Yes | Yes | No | No |
This routine initializes SIMM with the value of SIML if SIML type is CONSTANT link or creates a channel access link if SIML type is PV_LINK. SVAL is likewise initialized if SIOL is CONSTANT or PV_LINK.
This routine next checks to see that device support and a device support read routine are available. If device support includes init_record, it is called.
If SGNL is changed, add_count is called.
If ULIM or LLIM are changed, WDTH is recalculated and clear_histogram is called.
If CMD is less or equal to 1, clear_histogram is called and CMD is reset to 0. If CMD is 2, CSTA is set to TRUE and CMD is reset to 0. If CMD is 3, CSTA is set to FALSE and CMD is reset to 0.
clear_histogram zeros out the histogram array. add_count increments the frequency in the histogram array.
Name | Summary | Description |
---|---|---|
PACT | Processing Active | See Chapter 2, Fields Common to All Record Types for an explanation of these fields. |
DPVT | Device Private | |
UDF | VAL Undefined | |
NSEV | New Alarm Severity | |
NSTA | New Alarm Status | |
SVL | Signal Value | The device support module retrieves a value from SGNL for SVL |
SGNL | Signal Value Location |
init_record(precord)This routine is called by the record support init_record routine. It makes sure that SGNL is a CONSTANT, PV_LINK, DB_LINK, or CA_LINK. It also retrieves a value for SVL from SGNL. If SGNL is none of the above, an error is generated.
read_histogram(*precord)This routine is called by the record support routines. It retrieves a value for SVL from SGNL.
Soft Channel
is currently provided, though other device support modules may be provided at the user's site.Soft Channel
device support routine retrieves a value from SGNL. SGNL must be CONSTANT, PV_LINK, DB_LINK, or CA_LINK.
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