DIN 70121

DIN 70121 is the DC-only predecessor of ISO 15118-2, used by many CCS chargers and vehicles in the field. ChargeLink plays both roles over IPv6 SDP, TCP, V2GTP and EXI. As vehicle, the din-evcc command runs one DC session against your charger, with a current-demand loop. As charger, ChargeLink runs plant-coupled on the NI VeriStand bench. DIN 70121 has no TLS, and none is offered.

Before you start

Requirement	What you need
Hardware	A Windows PC for ChargeLink with an Ethernet adapter on the link to the other side. For the charger role: the NI VeriStand bench of the package. A powerline (PLC) link needs the hardware described in Connecting to Real PLC Hardware.
Network	IPv6 enabled on that adapter; link-local addresses (`fe80::/10`), no router. UDP 15118 (SDP) and the TCP port of the session open in Windows Firewall for `fe80::/10` (Install and Activate); the DIN 70121 charger listens on TCP 50119 by default. Run the preflight.
Licence	An active ChargeLink licence on the ChargeLink PC (`chargelink --json license status`). A command that needs it stops with exit code 20 (`CL-LICENSE-001`).
TLS material	None. DIN 70121 runs on plain TCP.

$CL   = 'C:\Program Files\DEVlink\ChargeLink\<VERSION>\charger\bin\chargelink.exe'
$Data = "$env:ProgramData\DEVlink\ChargeLink\data"
$IfIndex   = <INTERFACE_INDEX>
$Advertise = 'fe80::<ADDRESS>%' + $IfIndex

The kit has a charger\ and a vehicle\ folder; chargelink.exe is the same binary in both.

ChargeLink as charger

In 0.5.0 the DIN 70121 charger runs plant-coupled on the NI VeriStand HIL bench. A standalone DIN charger with a built-in plant model is not part of 0.5.0. The charger is verified on the bench with ChargeLink's own DIN 70121 vehicle.

The charger profile is din70121_dc. evse start --protocol din70121 --profile-id din70121_dc runs only plant-coupled: it needs --plant-grpc-endpoint (the bench's plant endpoint), --requested-power-kw, --target-voltage-v and the safety link to the plant owner of the bench, and does not start without them. The bench set-up is described in NI VeriStand Bench.

Option	Meaning
`--tcp-port`	The charger's TCP port (default 50119 for DIN 70121).
`--udp-port 15118`	The SDP port.
`--interface-index`, `--advertise-ipv6`	The interface to the vehicle and the link-local address placed in the SDP response.
`--max-runtime-ms`	Runtime limit of the listener.
`--json`	Machine-readable result.

There is no TLS: --tls is refused.

What a good session looks like

The charger writes its own run folder under its --artifact-root. On the NI VeriStand bench the session result is read as described in Reading the result.

ChargeLink as vehicle

Your DUT is a charger or SECC. Connect it to the ChargeLink PC's adapter. din-evcc is the standalone DIN 70121 vehicle: one nominal DC session per run, over TCP only (no TLS), with no plant. There are no EV cases or profiles; the options below shape the session.

# with SDP: multicast discovery on the interface to the charger
chargelink --runtime-root "$Data\runtime" --artifact-root "$Data\artifacts" --json din-evcc --sdp-server "[ff02::1%$IfIndex]:15118" --run-id din-ev-<DATE>

# with the charger's own SDP address
chargelink --runtime-root "$Data\runtime" --artifact-root "$Data\artifacts" --json din-evcc --sdp-server "[fe80::<CHARGER_ADDRESS>%$IfIndex]:15118" `
  --target-voltage-v 400 --target-current-a 100 --current-demands 20 --run-id din-ev-<DATE>

# without SDP: straight to the charger's TCP port
chargelink --runtime-root "$Data\runtime" --artifact-root "$Data\artifacts" --json din-evcc --peer "[fe80::<CHARGER_ADDRESS>%$IfIndex]:<CHARGER_TCP_PORT>" --run-id din-ev-<DATE>

$IfIndex is the Windows interface number of the Ethernet port to the charger. Give either --sdp-server or --peer, not both.

Option	Meaning
`--sdp-server` / `--peer`	Discover the charger through SDP (`[ff02::1%<ifIndex>]:15118` or the charger's own SDP address), or connect to its TCP port directly.
`--target-voltage-v`, `--target-current-a`	The vehicle's targets (defaults 400 V, 100 A). Set the target voltage to what your charger can deliver: PreCharge waits for it.
`--max-voltage-v`, `--max-current-a`, `--max-power-w`	The vehicle's limits (defaults 500 V, 200 A; maximum power defaults to maximum voltage times maximum current).
`--current-demands N`	CurrentDemandReqs before the vehicle stops (default 20); `0` keeps requesting until the charger stops.
`--period-ms`	Time from a CurrentDemandRes to the next CurrentDemandReq (100 to 900 ms, default 150).
`--no-welding-detection`	Skip the optional WeldingDetection.
`--expect-stop-tail`	Accept an orderly early stop by the charger.
`--connect-timeout-ms`	Connection timeout (default 2000 ms).
`--artifact-root`, `--runtime-root`	Where the run folder and the runtime state are written (defaults `.chargelink\artifacts` and `.chargelink\runtime`).

What a good session looks like

The command exits with code 0. Otherwise it exits non-zero and its last line reads "DIN 70121 EVCC session did not end as asked: …".
It prints one JSON line, also saved as <artifact-root>\<run-id>\din_evcc_report.json: passed (SessionStop answered OK with no stop reason, a planned stop), accepted (passed, or with --expect-stop-tail an orderly early stop) and run (session details and any error).
traces\live-v2gtp-frames.jsonl has one line per message with timestamps and payload hashes (no payload contents).
If the charger is lost in mid-session, the run ends at once with a non-zero exit.

The reference vehicle profiles (din70121_dc_evcc_reference, din70121_evcc_reference) send a ChargeLink-specific encoding that a real charger does not decode. Use them for dry-run and deterministic simulation only.

Results and evidence

Each run writes one folder under the artifact root, $Data\artifacts\<run-id>. Judge a vehicle run by din_evcc_report.json, then check that no file changed after the run:

chargelink --runtime-root "$Data\runtime" --artifact-root "$Data\artifacts" --json artifacts integrity --run-id din-ev-<DATE>

See Trace, Evidence and Reports. Deterministic simulation for ISO 15118-2 and DIN 70121 is available on request through DEVlink support.

ChargeLink's DIN 70121 implementation interoperated with an independent open-source DIN implementation in DEVlink's own tests. This is not certification.

Limits

DIN 70121 is DC-only. AC tests use ISO 15118-2 or ISO 15118-20.
No TLS; DIN 70121 defines none.
The charger runs plant-coupled on the NI VeriStand HIL bench only, and is verified there with ChargeLink's own DIN 70121 vehicle. A standalone DIN charger with a built-in plant model is not part of 0.5.0.
The vehicle (din-evcc) runs one nominal DC session per run; it has no EV cases or profiles.
No physical charging interface (control pilot, PWM, PLC/SLAC, power stage) is included.

See Capability Boundaries. To check the installation without a DUT, see Self-test without a device under test.

Troubleshooting

Symptom	Usually means	Action
`evse start` refuses `din70121_dc`	The plant-coupled profile needs `--plant-grpc-endpoint`, `--requested-power-kw`, `--target-voltage-v` and the plant owner's safety link	Run the charger on the NI VeriStand bench.
`evse start` refuses `--tls`	DIN 70121 has no TLS	Remove the TLS options.
`din-evcc` waits in PreCharge, then fails	The target voltage is outside what the charger delivers	Set `--target-voltage-v` to a voltage your charger can deliver.
`din-evcc` exits non-zero after the charger stopped early	The charger ended the session before the planned stop	Read `run` in `din_evcc_report.json`; add `--expect-stop-tail` if an orderly early stop is expected.
`din-evcc` refuses its arguments	Both `--sdp-server` and `--peer` were given	Give one of them.
Your charger does not decode ChargeLink's vehicle messages	A reference vehicle profile was used	Use `din-evcc`.

General failures (licence, ports, firewall, role locks) are in Troubleshooting.