EPICS stands for Experimental Physics and Industrial Control System. It is a set of open source, distributed software tools used extensively for scientific instruments such as particle accelerators, telescopes, and other large-scale experimental installations. Using EPICS, scientists are able to network together arbitrarily complex systems of nodes, such as motion controllers, PLCs, instrumentation, and other software and hardware agents. Using a read/write protocol called Channel Access, the Input/Output controllers (IOCs), can interact while providing high-level functionality and interaction for sophisticated physics applications.
Galil now offers the EPICS Driver Baseline. As shown in Illustration 1, this software provides communication drivers and device support to create a Galil EPICS IOC. The software comes with the basic support needed for building a feature-rich IOC including the following:
- Support for the DMC-3x01x, DMC-4000, and DMC-41x3 Ethernet based controllers. Galil communications libraries allow extension to PCI-based controllers such as the DMC-18x6, DMC-18x2, and DMC-18x0. The array access feature allows easy extension to Galil's line of RIO-47xxx PLCs.
- Basic Motor Record Support, which is an EPICS IOC Record designed specifically for motion controllers. See Table for some example fields imn the EPICS Motor Record.
Using the EPICS Channel Access feature, Galil array data can be read and written directly from the EPICS network. Coupled with DMC code embedded on the controller, the EPICS user can easily extend the EPICS support to any desired Galil firmware feature or programmable function. The array access feature, which is part of the Galil EPICS driver, allows quick deployment in an EPICS system without requiring a deep knowledge of EPICS IOC development.
For step-by-step instructions on integrating a Galil controller or RIO PLC into an EPICS platform, e-mail Galil Applications Enginneering at support@galil.com or call (800) 377 6329. More information can also be found on the EPICS product page.
| Field | Description |
|---|---|
| ACCL | Acceleration, Deceleration specified in seconds. Duration of the accel/decel region. |
| ATHM | At home. State of HM input. |
| DHLM | Dial High Limit. Essentially a soft forward end of travel. |
| DLLM | Dial Low Limit. Essentially a soft reverse end of travel. |
| DMOV | Motion complete Boolean. 1 = finished; 0 = moving.Uses motion complete bit from data record. |
| EGU | Engineering units. Galil baseline normalized to counts/steps. |
| ERES | Encoder step size in EGU |
| HOMF | Home Forward. Set to 1 to initiate home. |
| HOMR | Home Reverse. Set to 1 to initiate home. |
| HVEL | Homing velocity. |
| ICOF | Integral Gain (KI normalized). Valid range; 0.0 <= ICOF <= 1.0 |
| JAR | Jog Acceleration (EGU/s/s). |
| JOGF | Jog motor forward. Set to 1 to initiate jog forward. |
| JOGR | Jog motor reverse. Set to 1 to initiate jog reverse. |
| JVEL | Jog Velocity. |
| MRES | Motor step size (EGU) |
| PCOF | Proportional Gain |
| REP | Raw Encoder Position |
| RMP | Raw Motor Position. The contents of the hardware's step-count register. Maps to Galil TD. |
| STOP | Stop motion. Set to 1 to initiate stop (ST) |
| VAL | Desired position. Will call a PA/PR to move the motor. |
| VELO | Velocity (EGU/s) |
| VMAX | Max Velocity (EGU/s) |
Table 1: Examples of helpful Motor Record Fields