fix(examples): use correct EtherCAT configured station address in ethercat-real-bus

examples/ethercat-real-bus/README.md

@@ -21,10 +21,14 @@ does NOT run it (no NIC, no EK1100 in CI).
   NIC to the EK1100's **IN (X1)** port. The OUT (X2) port is for
   daisy-chaining additional couplers; leave it empty.
 
-> **Topology assumption.** The example pins the EL1008 to SubDevice
-> address `1` (the EK1100 is index `0` with no PDI). If you have
-> additional terminals between the EK1100 and EL1008, edit the
-> `SUBDEV` constant in `src/main.rs`.
+> **Topology assumption.** The example pins the EL1008 to the EtherCAT
+> configured station address `0x1001`. `ethercrab` auto-assigns these
+> starting at `0x1000` in bus-scan order, so EK1100 = `0x1000`,
+> EL1008 = `0x1001`, EL2004 = `0x1002`, etc. The driver matches on
+> the configured station address (not a 0-based topology index), so
+> this needs to be the real EtherCAT address. If you have additional
+> terminals between the EK1100 and EL1008, edit the `SUBDEV` constant
+> in `src/main.rs` accordingly.
 
 ## Host setup
 
@@ -72,20 +76,49 @@ Or cap the run length for a quick smoke test (each tick is the
 
 ## What you should see
 
+Bring-up, then (if any inputs are wired) one change-event per
+transition on the EL1008's 24 V inputs. The excerpt below is from a
+Pi 5 walking a 24 V probe across the eight input channels in order —
+captured on the documented topology plus an extra EL2004 between the
+EL1008 and the end cap:
+
 ```
+0 [W] "Config::global_config()"
+ | No config file was loaded, a config with default values will be used.
 ethercat connector health at startup: Connecting
+t=+   531ms  bits=0b00000000  decimal=0
 ethercat connector health: Connecting -> Up
-t=+    12ms  bits=0b00000000  decimal=0
-t=+  1842ms  bits=0b00000001  decimal=1
-t=+  2103ms  bits=0b00000011  decimal=3
-...
+ethercat connector health: Up -> Degraded
+t=+ 23510ms  bits=0b00000001  decimal=1
+t=+ 23650ms  bits=0b00000000  decimal=0
+t=+ 25360ms  bits=0b00000010  decimal=2
+t=+ 25780ms  bits=0b00000000  decimal=0
+t=+ 27170ms  bits=0b00000100  decimal=4
+t=+ 27460ms  bits=0b00000000  decimal=0
+t=+ 28580ms  bits=0b00001000  decimal=8
+t=+ 28840ms  bits=0b00000000  decimal=0
+t=+ 30190ms  bits=0b00010000  decimal=16
+t=+ 30410ms  bits=0b00000000  decimal=0
+t=+ 31370ms  bits=0b00100000  decimal=32
+t=+ 31610ms  bits=0b00000000  decimal=0
+t=+ 33730ms  bits=0b01000000  decimal=64
+t=+ 33960ms  bits=0b00000000  decimal=0
+t=+ 34730ms  bits=0b10000000  decimal=128
+t=+ 34881ms  bits=0b00000000  decimal=0
 ```
 
-Bring-up usually completes within 1–2 seconds on a Pi 4. If you see
-only `Connecting -> Up` and then no further output, that's expected
-with no inputs wired — the EL1008 just reports all zeros. The bus is
-alive; press a button on any 24V input channel to watch the byte
-change.
+Bring-up usually completes within 1–2 seconds on a Pi 4 or 5. With
+no inputs wired the EL1008 just reports all zeros — bring-up still
+runs to completion, the initial `bits=0b00000000` line prints, and
+nothing further appears until you touch 24 V to one of the input
+channels.
+
+The `Up -> Degraded` line above is rig-specific: adding an output
+terminal such as the EL2004 without writing to it makes the working
+counter come back lower than ethercrab expects, which trips the
+connector's asymmetric-PDO degradation flag. Reads from the EL1008
+keep flowing. With the bare EK1100 + EL1008 topology this README
+documents you stay at `Up` and never see the `Degraded` transition.
 
 ## Troubleshooting
 

examples/ethercat-real-bus/src/main.rs

@@ -2,11 +2,12 @@
 //! EK1100 + EL1008 over a real Linux NIC. See README.md for hardware
 //! setup and run instructions.
 //!
-//! Topology assumption: EK1100 is SubDevice 0 (no PDI; it's a bus
-//! coupler) and the EL1008 is SubDevice 1 with an 8-bit Tx PDO at
-//! bit offset 0. If your topology has additional terminals between
-//! the EK1100 and EL1008, edit `SUBDEV` to the EL1008's actual
-//! auto-incremented address.
+//! Topology assumption: `ethercrab` assigns configured station
+//! addresses starting at `0x1000` — EK1100 = `0x1000` (no PDI; it's
+//! a bus coupler), EL1008 = `0x1001` with an 8-bit Tx PDO at bit
+//! offset 0. If your topology has additional terminals between the
+//! EK1100 and EL1008, edit `SUBDEV` to the EL1008's actual
+//! configured station address.
 
 use core::time::Duration;
 use std::sync::{Arc, Mutex};
@@ -24,11 +25,14 @@ use taktora_executor::{ControlFlow, ExecuteResult, Executor, ExecutorError, item
 /// Channel capacity (iceoryx2 service buffer slots).
 const N: usize = 256;
 
-/// EL1008's auto-incremented EtherCAT SubDevice address. With a bare
-/// EK1100 + EL1008 the EL1008 lands at index 1 (the EK1100 is index 0
-/// with no PDI). Adjust if you have additional terminals between
-/// them.
-const SUBDEV: u16 = 1;
+/// EL1008's EtherCAT configured station address. `ethercrab`'s
+/// `init_single_group` assigns auto-incrementing addresses starting
+/// at `0x1000` (EK1100 = 0x1000, EL1008 = 0x1001, EL2004 = 0x1002,
+/// etc.). The driver matches on `sd.configured_address()`, not the
+/// topology index, so this needs to be the actual EtherCAT station
+/// address — not `1`. Adjust if you have additional terminals
+/// between the EK1100 and EL1008.
+const SUBDEV: u16 = 0x1001;
 
 /// 8 digital input bits, one PDI byte.
 const ROUTING_BITS: u16 = 8;
@@ -139,9 +143,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let state = Arc::new(EthercatState::new(opts.clone()));
     let mut connector = EthercatConnector::new(state, driver, RawByteCodec)?;
 
-    // 4. Routing — EL1008 inputs at SubDevice 1, bit offset 0, 8 bits.
-    //    PdoDirection::Tx means the SubDevice writes (Tx) and the
-    //    master reads.
+    // 4. Routing — EL1008 inputs at configured station address
+    //    `0x1001`, bit offset 0, 8 bits. PdoDirection::Tx means the
+    //    SubDevice writes (Tx) and the master reads.
     let routing = EthercatRouting::new(SUBDEV, PdoDirection::Tx, 0, ROUTING_BITS);
     let desc =
         ChannelDescriptor::<EthercatRouting, N>::new("ethercat.el1008.inputs", routing)?;