A hardware change to the SNAP-PAC-R1 unit increases support from 32 to 64 high-speed digital I/O points. The high-speed digital I/O features include:
· high-speed counting
· quadrature counting
· on-pulse and off-pulse measurement
· pulse generation
On a 16-position rack such as the SNAP-M64, any position on the rack can support a digital module. Prior to the design change, you could only install a digital module in the first 8 positions of the mounting rack.
SNAP-PAC-R1 firmware has an auto-detect feature to determine if the I/O unit hardware supports 32 or 64 points of digital I/O. This allows newer firmware to run on any the SNAP-PAC-R1 hardware version.
How to identify newer SNAP-PAC-R1 units
· Inspect the serial number stamped on the SNAP-PAC-R1 case. Units with serial numbers 600000 and above, have the new design.
· PAC Manager can also be used to inspect the I/O Unit Hardware Revision information by selecting Tools→Inspect, to view the Inspect I/O Unit page. SNAP-PAC-R1s with the updated design have the following hardware revisions listed:
0xFFFF F030 0024
I/O Unit Hardware Revision (Month)
0xFFFF F030 0025
I/O Unit Hardware Revision (Day)
0xFFFF F030 0026
I/O Unit Hardware Revision (Year)
· You can also inspect memory map location 0xF0300148 with PAC Manager to find out how many digital modules are supported. The values read will be 0, 8, or 16.
To inspect this location with PAC Manager use Tools→Inspect, Other→Generic Read/Write, enter the memory map location in the Address field, and click Refresh. If the value read is 8, then 32 digital I/O points are supported; if the value is 16, 64 digital I/O points are supported. If this memory map location does not exist, then only 8 digital modules are supported in the first 8 positions of the mounting rack.