7-17
7.29: ElectroLogic Block (46421-46804)
An EPM device will support 16 Relay structures.
QΕach Relay Structure will combine up to 8 Limit Comparisons or Combinations using a three-level
binary tree of AND, OR, NAND, NOR, XOR or Hysteresis combinations. All trees will be
reevaluated once per second. The final result of the tree, subject to delays, would then be queued for
immediate transmission to External Relay Output devices.
Information needed to perform these actions:
•Input Limit Comparison and Combination Identification
•Input Senses for Each Input
•Combination Assignments for Each of 7 Gates in the Tree for Each Relay Structure
•Delay Times
QInput Sense would apply to each input, negating an input state; in effect this would be the
above/below equivalent for non-limit inputs like low speed inputs.
QComparison and combination identification would be performed by referencing the internal data
table of the EPM, by specifying the Line number and Point number for a particular bit. For
example, to refer to the first comparison of Limit 1, use Line 231, Point 0; first comparison of Limit
2, use Line 231, Point 1; first comparison of Limit 20, use Line 231, Point 19; second comparison of
Limit 1, use Line 232, Point 0. To leave a line unassigned with a value of 0, use Line 65535, Point
255.
Binary Tree combinations: AND, OR, NAND, NOR, XOR and Hysteresis.
Delays are in seconds, and with a separate delay for activation (0-to-1 transitions) and deactivation
(1-to-0 transitions).
QThe format of a Relay Structure:
2 byte Line Number, First Tree Input
1 byte Point Number, First Tree Input
1 byte Unused
This 4 byte structure is repeated 7 more times for a total of eight inputs, 32 bytes.
1 byte Input sense & combination A, combining inputs 1 & 2
1 byte Input sense & combination B, combining inputs 3 & 4
1 byte Input sense & combination C, combining inputs 5 & 6
1 byte Input sense & combination D, combining inputs 7 & 8
1 byte Input sense & combination E, combining A& B
1 byte Input sense & combination F, combining C & D
1 byte Input sense & combination G, combining E & F
1 byte Unused
1 byte Delay in seconds from 0-to-1 transition before reporting 1
1 byte Delay in seconds from 1-to-0 transition before reporting 0
6 bytes Unused
Total of 48 bytes per Relay Structure, total of 768 bytes for 16 Relay Objects.