Counterbox Epics Module
-----------------------

A Stream and Asyn based driver for Counterboxes as SINQ.

This supports the older 4 and 8 channel EL737 models and the new 10CH 2nd
generation systems.

## How to Use

Unless a custom database is needed, a device can be configure simply by setting
the required environment variables when calling the correct counterbox script.

Required Variables

| Environment Variable | Purpose                                 |
|----------------------|-----------------------------------------|
| PREFIX               | Prefix of all device specific PVs       |
| NAME                 | First field in all PVs after Prefix     |
| ASYN_PORT            | Unique name for referencing Asyn device |
| CNTBOX_HOST          | Network IP and Port of device           |

All PVs take the form

```
$(PREFIX):$(NAME):*
```

Available device startup scripts

* scripts/counterbox_4ch.cmd
* scripts/counterbox_8ch.cmd
* scripts/counterbox_v2.cmd

A device can be configured using one of the startup scripts as follows

```
epicsEnvSet("PREFIX", "SQ:INSTRUMENT") # can also be set in runScript call

runScript "$(counterbox_DIR)counterbox_v2.cmd" "NAME=COUNTERBOX, ASYN_PORT=CBOXV2, CNTBOX_HOST=TestInst-DAQ1:2000"
```

## PVs of Interest

| PV                                    | Description                                                          |
|---------------------------------------|----------------------------------------------------------------------|
| \$(PREFIX):\$(NAME):MsgTxt            | Contains unexpected response to executed command                     |
| \$(PREFIX):\$(NAME):STATUS            | 0: Idle, 1: Counting, 2: Low rate, 3: Paused, 4: Error               |
| \$(PREFIX):\$(NAME):MONITOR-CHANNEL   | Channel that PRESET-COUNT monitors (has RBV, only v2 can be changed) |
| \$(PREFIX):\$(NAME):PRESET-COUNT      | Run count until specified pv value reached                           |
| \$(PREFIX):\$(NAME):PRESET-TIME       | Run count until specified pv value in seconds reached                |
| \$(PREFIX):\$(NAME):THRESHOLD         | Minimum rate for counting to preceed. (has RBV)                      |
| \$(PREFIX):\$(NAME):THRESHOLD-MONITOR | Channel monitored for minimum rate (has RBV)                         |
| \$(PREFIX):\$(NAME):ELAPSED-TIME      | Time Counterbox has been measuring for                               |
| \$(PREFIX):\$(NAME):M_                | Current count on channel. (1-10 depending on box)                    |
| \$(PREFIX):\$(NAME):CHANNELS          | Number of available channels (4, 8 or 10)                            |