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TAMsys — Asset Monitoring SystemTAMsys Developer

MQTT & HTTPS publishing

TAMsys accepts device telemetry through AWS IoT Core in the ap-south-1 region. MQTT and HTTPS use the same device endpoint, X.509 credentials, topic, and payload; their ports and connection models differ.

Endpoint and topic

Section titled “Endpoint and topic”
Setting Value
Endpoint hostname a27pmjgdoz4ztv-ats.iot.ap-south-1.amazonaws.com
Authentication Mutual TLS with an X.509 client certificate
Publish topic tessol/tamsys/{device_id}
MQTT port 8883
HTTPS publish port 8443

Use the hostname without a scheme in MQTT client configuration. For HTTPS, use the full https:// URL shown below.

Required credentials

Section titled “Required credentials”

Both transports require:

  1. A device certificate issued or registered for the TAMsys AWS IoT account.
  2. The matching private key.
  3. An Amazon Root CA trusted by the AWS IoT Core ATS endpoint.
  4. An active certificate with an attached IoT policy that permits publishing to the provisioned device topic.

MQTT connections also require the policy’s iot:Connect permission. Request device provisioning material from TAMsys support.

MQTT over TLS

Section titled “MQTT over TLS”

MQTT uses a persistent connection to a27pmjgdoz4ztv-ats.iot.ap-south-1.amazonaws.com:8883. Use a unique client ID for every simultaneous connection.

Terminal window
mosquitto_pub \
  --host a27pmjgdoz4ztv-ats.iot.ap-south-1.amazonaws.com \
  --port 8883 \
  --cafile AmazonRootCA1.pem \
  --cert device-certificate.pem.crt \
  --key private.pem.key \
  --id 'device-client-id' \
  --topic 'tessol/tamsys/DEVICE_ID' \
  --qos 1 \
  --message '{"id":"DEVICE_ID","utctimestamp":1785488704000,"temp":4.6}'

Replace the filenames, client ID, device ID, and payload with provisioned values.

HTTPS publish

Section titled “HTTPS publish”

AWS IoT Core’s HTTPS device API accepts publish-only POST requests. Put the topic after /topics/ and select QoS with the qos query parameter:

https://a27pmjgdoz4ztv-ats.iot.ap-south-1.amazonaws.com:8443/topics/tessol/tamsys/{device_id}?qos=1

The port 8443 endpoint accepts X.509 mutual TLS directly and does not require the custom ALPN protocol name needed for X.509 authentication on port 443.

Terminal window
curl --silent --show-error --fail-with-body \
  --tlsv1.2 \
  --cacert AmazonRootCA1.pem \
  --cert device-certificate.pem.crt \
  --key private.pem.key \
  --request POST \
  --header 'Content-Type: application/json' \
  --data-binary '{"id":"DEVICE_ID","utctimestamp":1785488704000,"temp":4.6}' \
  'https://a27pmjgdoz4ztv-ats.iot.ap-south-1.amazonaws.com:8443/topics/tessol/tamsys/DEVICE_ID?qos=1'

A successful publish returns HTTP 200 with an empty response body. This confirms that AWS IoT Core accepted the message; it does not confirm downstream TAMsys processing. Treat the complete topic as the value after /topics/ when building the URL. Clients may percent-encode it as tessol%2Ftamsys%2FDEVICE_ID; AWS’s port 8443 examples also show literal / separators in the topic path.

See AWS’s HTTPS publish example for the request format and its protocol and port table for authentication requirements.

Choose a transport

Section titled “Choose a transport”
Requirement MQTT over TLS HTTPS publish
Connection Persistent session One stateless request per publish
AWS IoT operations Publish and subscribe Publish only
Client ID Required and unique while connected Not used
QoS MQTT QoS 0 or 1 qos=0 or qos=1 query parameter
Best fit Frequent telemetry and long-lived device sessions Infrequent or batched publishing without an MQTT client

HTTPS has a TLS and HTTP setup cost for each request unless the client reuses its connection. For frequent small messages, MQTT is generally more efficient. Provisioned TAMsys IoT policies can be narrower than the AWS IoT protocol capabilities shown in the table.

Troubleshooting

Section titled “Troubleshooting”
Symptom Check
TLS handshake fails ATS root CA, client certificate/private key pairing, certificate validity, and device clock
MQTT connection is rejected Certificate status, attached policy, unique client ID, endpoint, and iot:Connect permission
Publish is rejected or HTTPS returns 401/403 Topic spelling, certificate status, and iot:Publish permission for tessol/tamsys/{device_id}
HTTPS returns 404 Port 8443, the /topics/ path, and the complete topic in the URL
Data does not appear JSON validity, matching id, millisecond timestamp, and TAMsys device assignment