FEC DSP1500 Main Unit User Manual
Page 55
enFORCE
DSP1500 Main Unit Hardware Manual
PAGE 5 - 15
(Rev. 4.0)
Chapter 5: Control Interfaces
5.3.4.1 Ouput Data Banks
When working with the Discrete I/O interface, the output signals are programmed into
“Banks” of 32 output signals in up to 8 output “Banks” (Max. 256 outputs). If the required
output signals from the Main Unit exceed 32 signals, then Bank 2 can be programmed
with additional signals. If over 64 signals are required, Bank 3 can be programmed and
so on. These Output “Banks” can then be selected by the Data Select input signals. The
Data Select input signals 0, 1 & 2 together form a binary code to select up to eight (8)
different Data Banks. (See Table 3 below)
Note
: Bank Select inputs do not function with any interface except the Discrete I/O
interface. When using Bank selects, it is recommended that the bank number be
monitored to confirm actual output status of shared discrete output points. This can be
performed by using the “Always On / Always Off” bits set-up in specific discrete output
points when programming the output points with the DSP User Console Software. For
this function, program the “Always On / Always Off” bits to mimic the Data Select input
bits. “Always On” bits will turn on the output in that particular Bank as soon as the bank
is selected. “Always Off” bits will turn off the output in the particular Bank which is
selected. Using different combinations of these bits programmed in an output in each
Bank will allow monitoring of which Bank is selected.
The number of discrete outputs used for this monitoring function depends on how many
Banks are required as shown below:
Number of Banks Required
Number of Discrete Outputs Required
1 0
or
1
2-4 2
5-8 3
Typically these “Always On / Always Off” bits are programmed in the last output points
(Pins 30 -32 as shown on the previous page).
[Table
3]
Output
Data
(BANK)
Selection
Data Select 2
Data Select 1
Data Select 0
Output Data Bank
OFF OFF OFF 0
OFF OFF ON
1
OFF
ON OFF 2
OFF
ON
ON
3
ON OFF OFF 4
ON OFF ON
5
ON
ON OFF 6
ON
ON
ON
7