^RS — RFID Setup
Plain English
**Configures the RFID encoder before any read or write** in the same label format. The first parameter `t` selects the **tag protocol** the encoder will use to talk to the inlay — `8` is **Gen2** (EPC Class-1 Gen-2, the dominant UHF standard, used by virtually every modern RFID label). Older protocols still selectable: `1` ISO 18000-6B, `4` Gen1, `5` ISO 18000-6A, `6` UCODE EPC 1.19. The remaining parameters tune **encoder retry / void behaviour**: `e` voided-label count limit, `n` numeric retry count for write failures, `a` antenna port (multi-antenna encoders only). Without an `^RS` in the format, the encoder runs on whatever defaults the firmware was configured with — which may not match the inlay protocol, silently fail, and ship blank or mis-encoded labels.
When to use
**Send `^RS` once at the top of every RFID format**, before any `^RF`/`^RT`/`^RW`/`^RZ` operation. The Gen2 default `^RS8` is the right answer for ~99% of modern UHF inlays (any chip from Impinj Monza, NXP UCODE, Alien Higgs families). Set `e` (voided-label limit) to control batch-failure handling — when `e` consecutive labels fail to encode the printer halts (default is usually 3); raise it for unreliable inlay batches, lower it to fail-fast in production. The `n` retry count works per-label, not per-batch. Cross-references: `^RF` (read/write), `^RT` (read tag), `^RZ` (lock memory), `^WT`/`^WV` (verify written data).
Syntax
^RSt,p,v,n,e,a,c,s
Parameters
| Parameter | Description |
|---|---|
t | Tag protocol: `8` Gen2 (default, recommended), `1` ISO 18000-6B, `4` Gen1, `5` ISO 18000-6A, `6` UCODE EPC 1.19 |
p | Position of the RFID label (start position offset in dots) — for printers where the encoder is offset from the print head; default depends on printer model |
v | Length of the void message (dots) printed across a failed label; `0` disables voiding |
n | Number of retries per label before declaring a write failure (typical 3) |
e | Voided-label count limit — printer halts after this many consecutive voids (typical 3) |
a | Antenna port for multi-antenna encoders (1–8 model-dependent); usually omitted |
c | Reserved / `^RS` continuation flag (firmware-specific) |
s | Reserved / additional setup field (firmware-specific) |
Example
^XA ^RS8,,,,5 ^RFW,H,0,12,0 ^FD3034257BF7194E4000001A85^FS ^XZ
Selects Gen2 protocol (`t=8`), leaves position/void/retry at firmware defaults, sets the voided-label count limit to 5 (`e=5`) — printer will void up to 5 labels in a row before halting on a bad inlay batch. The subsequent `^RFW` write into the EPC bank uses this configuration.