Remote Isolated Field I-O Card Targets Real-time Control Systems
Tue, 01/03/2012 - 7:31am
The MESA 7I66 is a remote isolated field I/O card designed for fast real time PC based control systems. The 7I66 communicates with the host with a robust isolated RS-422 link. Standard CAT5 cables are used for wiring convenience. The 7I66 is supported by Mesa's low cost FPGA cards which present a simple parallel register interface to the host, with all protocol details handled by the smart interface. One FPGA card can support up to 32 external devices and up to 3072 control points while still maintaining 10 kHz service rate for all points. The card is available in two models, the 7I66-24 and the 7I66-8. The 7I66-24 has 24 outputs and no inputs. The 7I66-8 has 8 outputs and 16 inputs. Outputs are 2.5 A sourcing drivers with 8 VDC to 32 VDC field power and local clamps for inductive loads. Instead of simple fixed threshold inputs, the 7I66 inputs are smart with variable threshold sensing. Default input threshold is 50 percent of field voltage with 20 percent hysteresis, but input thresholds are individually programmable from 0 VDC to 36 VDC. All I/O points have LED status indicators and removable screw terminal field wiring. The 7I66 is suited for high performance industrial automation and machine tool applications.