# `otopcua-ablegacy-cli` — AB Legacy (PCCC) test client

Ad-hoc probe / read / write / subscribe tool for SLC 500 / MicroLogix 1100 /
MicroLogix 1400 / PLC-5 devices, talking to the **same** `AbLegacyDriver` the
OtOpcUa server uses (libplctag PCCC back-end).

Third of four driver test-client CLIs. Shares `Driver.Cli.Common` with the
others.

## Build + run

```powershell
dotnet run --project src/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Cli -- --help
```

## Common flags

| Flag | Default | Purpose |
|---|---|---|
| `-g` / `--gateway` | **required** | Canonical `ab://host[:port]/cip-path` |
| `-P` / `--plc-type` | `Slc500` | Slc500 / MicroLogix / Plc5 / LogixPccc |
| `--timeout-ms` | `5000` | Per-operation timeout — see precedence note below |
| `--retries` | `0` | Retry count on transient `BadCommunicationError` (PR 9 / #252) |
| `--verbose` | off | Serilog debug output |

Family ↔ CIP-path cheat sheet:
- **SLC 5/05 / PLC-5** — `1,0`
- **MicroLogix 1100 / 1400** — empty path (`ab://host/`) — they use direct EIP
  with no backplane
- **LogixPccc** — `1,0` (Logix controller accessed via the PCCC compatibility
  layer; rare)

### Per-device timeout / retry tuning (#252, PR 9)

The CLI's `--timeout-ms` is the **driver-wide default** when launched as a
one-shot test client. In production (server-side, multi-device deployment)
each `AbLegacyDeviceOptions` row carries its own optional `Timeout` /
`Retries` that override the driver-wide value.

Precedence (highest → lowest): per-device override → driver-wide default →
hard-coded fallback (2000 ms / 0 retries).

Tuning cheat sheet — start here, measure, then trim:

| Family | Recommended `Timeout` | Notes |
|---|---|---|
| SLC 5/01 (RS-232 / DH+ bridge) | **5000 ms** | Slowest of the bunch; serial round-trip plus DH+ hop |
| SLC 5/02 / 5/03 (DH+) | 3000 ms | Bridged Ethernet → DH+ adds ~1 s |
| **SLC 5/04 / 5/05** (Ethernet) | **2000 ms** | Fastest of the SLC family — direct EIP/PCCC |
| MicroLogix 1100 / 1400 | **3000 ms** | Single-CPU, slow scan; no backplane |
| PLC-5 (Ethernet I/F) | 2500 ms | Comparable to SLC 5/05 over EIP |
| LogixPccc compat layer | 2000 ms | Logix CPU is fast; PCCC layer is the floor |

A small `--retries 1` (or `2` for slow chassis) is generally safe — the retry
loop only fires on transient `BadCommunicationError`; terminal errors
(`BadNodeIdUnknown`, `BadTypeMismatch`, …) surface on the first attempt.

## PCCC address primer

File letters imply data type; type flag still required so the CLI knows how to
parse your `--value`.

| File | Type | CLI `--type` |
|---|---|---|
| `N` | signed int16 | `Int` |
| `F` | float32 | `Float` |
| `B` | bit-packed (`B3:0/3` addresses bit 3 of word 0) | `Bit` |
| `L` | long int32 (SLC 5/05+ only) | `Long` |
| `A` | analog int (semantically like N) | `AnalogInt` |
| `ST` | ASCII string (82-byte + length header) | `String` |
| `T` | timer sub-element (`T4:0.ACC` / `.PRE` / `.EN` / `.DN`) | `TimerElement` |
| `C` | counter sub-element (`C5:0.ACC` / `.PRE` / `.CU` / `.CD` / `.DN`) | `CounterElement` |
| `R` | control sub-element (`R6:0.LEN` / `.POS` / `.EN` / `.DN` / `.ER`) | `ControlElement` |

## Commands

### `probe`

```powershell
# SLC 5/05 — default probe address N7:0
otopcua-ablegacy-cli probe -g ab://192.168.1.20/1,0

# MicroLogix 1100 — status file first word
otopcua-ablegacy-cli probe -g ab://192.168.1.30/ -P MicroLogix -a S:0
```

### `read`

```powershell
# Integer
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a N7:10 -t Int

# Float
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a F8:0 -t Float

# Bit-within-word
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a B3:0/3 -t Bit

# Long (SLC 5/05+)
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a L19:0 -t Long

# Timer ACC
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a T4:0.ACC -t TimerElement
```

### `write`

```powershell
otopcua-ablegacy-cli write -g ab://192.168.1.20/1,0 -a N7:10 -t Int -v 42
otopcua-ablegacy-cli write -g ab://192.168.1.20/1,0 -a F8:0 -t Float -v 3.14
otopcua-ablegacy-cli write -g ab://192.168.1.20/1,0 -a B3:0/3 -t Bit -v on
```

Writes to timer / counter / control sub-elements land at the wire level but
the PLC's runtime semantics (EN/DN edge-triggering, preset reload) are
PLC-managed — use with caution.

### `subscribe`

```powershell
otopcua-ablegacy-cli subscribe -g ab://192.168.1.20/1,0 -a N7:10 -t Int -i 500
```

#### Deadband

PR 8 — per-tag absolute / percent change filter on top of the polled subscription. The driver
caches the last *published* value per tag and suppresses `OnDataChange` notifications until the
new sample crosses the configured threshold.

| Flag | Effect |
|---|---|
| `--deadband-absolute <value>` | Suppress until `|new - prev| >= value`. |
| `--deadband-percent <value>` | Suppress until `|new - prev| >= |prev * value / 100|`. `prev == 0` always publishes (avoids div-by-zero). |

Booleans bypass the filter entirely (every transition publishes); strings + status changes
always publish; first-seen always publishes; both flags set → either passing triggers a
publish (Kepware-style logical OR).

```powershell
# Float — drop sub-0.5 jitter from the noisy load-cell address.
otopcua-ablegacy-cli subscribe -g ab://192.168.1.20/1,0 -a F8:0 -t Float -i 500 `
    --deadband-absolute 0.5

# Integer — only fire on >= 5% deviation from the last reported value.
otopcua-ablegacy-cli subscribe -g ab://192.168.1.20/1,0 -a N7:10 -t Int -i 500 `
    --deadband-percent 5
```

## Array reads

PR 7 — one PCCC frame can carry up to ~120 words. Address an array tag with either the
Rockwell-native `,N` suffix or the libplctag-native `[N]` suffix on the word number; both
forms canonicalise to `[N]` when the driver hands the tag to libplctag, and the parser
caps `N` at 120.

```powershell
# Rockwell `,N` form — "10 consecutive words starting at N7:0"
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a "N7:0,10" -t Int

# libplctag `[N]` form — same wire result
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a "N7:0[10]" -t Int

# Float / Long arrays — same suffix syntax, narrower frame ceiling on Float (~60 elements)
# and Long (~60 elements) because each element is 4 bytes vs Int's 2.
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a "F8:0,4" -t Float
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a "L19:0,4" -t Long

# --array-length override — pin the element count from config rather than the address
# suffix. Wins over the parsed `,N` / `[N]` value when both are set; useful for keeping the
# address string compact while bumping the element count from a tags config file.
otopcua-ablegacy-cli read -g ab://192.168.1.20/1,0 -a "N7:0" --array-length 10 -t Int
```

Array tags reject sub-element references (`T4:0,5.ACC`) and bit suffixes (`N7:0,10/3`) at
parse time — both combinations are semantically meaningless against a contiguous block.

For `B`-files the Rockwell convention is "one BOOL per word, not per bit": `B3:0,10`
returns `bool[10]` (one per word's non-zero state), not `bool[160]`.

## Known caveat — ab_server upstream gap

The integration-fixture `ab_server` Docker container accepts TCP but its PCCC
dispatcher doesn't actually respond — see
[`tests/...AbLegacy.IntegrationTests/Docker/README.md`](../tests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests/Docker/README.md).
Point `--gateway` at real hardware or an RSEmulate 500 box for end-to-end
wire-level validation. The CLI itself is correct regardless of which endpoint
you target.