ARRAY_TIMER

Studio 5000 Add-On Instruction - Rev 1.0

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Array-based multi-channel software timer with programmable delay. A single internal free-running TON drives up to 1,050 independent channels, each with its own delay preset and done flag.

Why This Exists

Standard Studio 5000 TIMER tags are large:

Approach	1,050 channels	Memory usage
Native TIMER tags	1,050 x 40 bytes	42,000 bytes
ARRAY_TIMER	Single AOI + arrays	~8,500 bytes

~5x smaller. One instance of ARRAY_TIMER replaces 1,050 native TIMER tags driven by a single free-running internal TON.

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Parameters

Parameter	Type	Direction	Description
CM_Inc	DINT	Input	Channel index (0-1049); used when AUTO_INC = 0
AUTO_INC	BOOL	Input	0 = manual index; 1 = auto-cycle 0 to 1049
PRE_IN	DINT	Input	Timer period in ms (shared by all channels; must be > 0)
Cond_EN	BOOL	Input	Rising edge starts delay; falling edge resets channel state
Delay_PRE	DINT	Input	Desired delay in ms (>= 0)
T_DN	BOOL	Output	One-scan pulse per timer period
T_ACC	DINT	Output	Live timer accumulator in ms
Delay_DN	BOOL	Output	True when delay has elapsed; held until Cond_EN drops
CM_Fault	BOOL	Output	Out-of-range index or PRE_IN <= 0; delay logic suspended
EFF_INC	DINT	Local (RO)	Active channel this scan - index your own arrays from other rungs

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Rung Map

Rung	Function
0	Header / overview NOP
1	Limitations (channel count, delay range, sweep time)
2	Index resolution
3	Auto-increment
4	Preset sync
5	Free-running timer (TON)
6	T_DN output
7	T_ACC output
8	Fault check
9	Landing point calculation (one-shot on Cond_EN rise)
10	Reset on disable
11	Cycle countdown
12	Done flag
13	Output (Delay_DN)

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How the Delay Works

On a Cond_EN rising edge, the AOI computes a landing point in the free-running timer cycle:

LANDING_PT = (T_ACC + Delay_PRE) MOD PRE_IN
COUNT      = floor((T_ACC + Delay_PRE) / PRE_IN)

COUNT decrements by one on every T_DN pulse. Delay_DN fires when COUNT = 0 and T_ACC >= LANDING_PT.

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Expanding Channel Count

1. Increase array dimensions of LANDING_PT, COUNT, FOUND, DN_FLAG.
2. Update CMP(EFF_INC > 1049) in Rung 8.
3. Update MOD 1050 in Rung 3.

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Requirements

• Studio 5000 / RSLogix 5000 v32.04+
• Any ControlLogix or CompactLogix controller

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Files

File	Description
ARRAY_TIMER.L5X	AOI export - import directly into Studio 5000
gen_aois_v2.py	Python generator script (regenerates both this AOI and ARRAY_CTUD)

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Related

• ARRAY_CTUD - same pattern applied to counters: 1,050 independent up/down counter channels, ~9x smaller than native COUNTER tags

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License

MIT - see LICENSE.