E0102 — RetimingDelayNotInteger - THRINDEX

E0102: synaptic delay cannot be retimed

What happened

The model uses synaptic delays authored at authored_dt. The compilation target uses a different target_dt. Retiming the delay from authored_dt to target_dt produces a non-integer number of steps, which cannot be represented.

Why

Delays are integer multiples of dt. If you scale delay_steps by authored_dt / target_dt, you must get an integer. For example:

delay=3 at dt=1ms → at dt=2ms → 3 × (1/2) = 1.5 — not an integer. Fails.
delay=4 at dt=1ms → at dt=2ms → 4 × (1/2) = 2 — integer. OK.

How to fix

Author the model at the target’s native dt: set dt=target_dt in the model. Then delays are written directly in the target’s step units.
Choose delays that divide evenly: if target_dt = authored_dt × k, use delays that are multiples of k.
Use the sim target: the simulator accepts any dt and runs delays exactly as authored.

Example

E0102: synaptic delay cannot be retimed in layer 0 connection 127
Why: delay_steps=3 × (authored_dt=1.0000 ms / target_dt=2.0000 ms) = 1.500000 is not an integer.
Fix: use a delay that is an integer multiple of target_dt / authored_dt, or author the model at target_dt directly.
Docs: https://docs.thrindex.com/errors/E0102