Industry Specific Health Level Seven International (HL7 v2.5 / FHIR R4)
HL7 v2.x & FHIR Healthcare Auto-ID Protocols
HL7 and FHIR ensure RFID events in hospitals (e.g., blood bag removal from a refrigerator or surgical tool autoclave sterilization) are formatted into compliant clinical messages and delivered to Epic, Cerner, or custom Laboratory Information Systems (LIS).
Layer / Stack
Application & MLLP (TCP 2575 / HTTPS REST)
Default Port / Freq
TCP Port 2575 (MLLP) | HTTPS REST API
Throughput / Speed
Instant real-time patient safety & specimen traceability
Standard Body
Health Level Seven International (HL7 v2.5
Core Protocol Architecture & Specifications
- ✓ Minimal Lower Layer Protocol (MLLP) framing: <VT> (0x0B) start byte and <FS><CR> (0x1C 0x0D) end bytes
- ✓ HL7 Segment Parsing: MSH (Message Header), EVN (Event Type), PID (Patient ID), and OBX (Observation/Result)
- ✓ FHIR R4 DeviceRequest and Specimen JSON resource representations for cloud EHR integration
- ✓ Automated refrigerated drug temperature logging and expiration date lockout
- ✓ Compliance with FDA Unique Device Identification (UDI) and Joint Commission surgical count protocols
HL7 v2.5 MSH/OBX Message Builder for RFID Cold Storage Alert
csharp public class Hl7RfidMessageBuilder
{
public static string CreateColdStorageObservation(string tagId, string drugName, float tempCelsius, string lotNumber)
{
string timestamp = DateTime.UtcNow.ToString("yyyyMMddHHmmss");
string messageControlId = Guid.NewGuid().ToString("N")[..10];
// MLLP Encapsulated HL7 v2.5 Message
var hl7 = new StringBuilder();
hl7.Append(" "); // <VT> Start Block
// MSH - Message Header
hl7.Append($"MSH|^~\&|RFID_EDGE_GATEWAY|PHARMACY_HUB|EPIC_HIS|CENTRAL_HOSPITAL|{timestamp}||ORU^R01|{messageControlId}|P|2.5\r");
// PID - Patient/Entity Context
hl7.Append($"PID|1||ASSET_PHARM_01^^^HOSPITAL||DRUG_INVENTORY||||||||||||||\r");
// OBR - Observation Request
hl7.Append($"OBR|1||RFID_SCAN_001|RFID_REFRIGERATOR_INVENTORY|||{timestamp}||||||||||||||||||\r");
// OBX - Observation Data (Tag EPC, Drug Name, Temp, Lot)
hl7.Append($"OBX|1|ST|TAG_EPC^RFID Tag Identifier||{tagId}||||||F\r");
hl7.Append($"OBX|2|ST|DRUG_NAME^Item Description||{drugName}||||||F\r");
hl7.Append($"OBX|3|NM|TEMP_C^Refrigeration Temp||{tempCelsius:F1}|degC|2.0-8.0|N|||F\r");
hl7.Append($"OBX|4|ST|LOT_NUMBER^Batch Lot||{lotNumber}||||||F\r");
hl7.Append("
"); // <FS><CR> End Block
return hl7.ToString();
}
}Verified Hardware Implementations
Our engineering team has thoroughly tested and validated HL7 & FHIR across the following reader models, embedded modules, and smart transponders:
Smart RFID Medicine Cabinets Autoclave Surgical Tray Readers Blood Bank Refrigerator RFID Grids Specimen Tube Rack Readers
Target Deployments
- Hospital pharmacy dispensing cabinets
- Surgical instrument sterilization loops
- Cold-chain blood bag & vaccine monitoring
- High-value biomedical equipment RTLS
Deploy with OpenRFID
Integrate HL7 & FHIR into your ERP, warehouse software, or custom mobile app with pre-built C# / C++ drivers.
What is MLLP in HL7 healthcare messaging?
MLLP (Minimal Lower Layer Protocol) is the standard TCP transport wrapper for HL7 v2 messages. It frames plain text segments between a vertical tab character (0x0B) and file separator + carriage return (0x1C 0x0D), ensuring the receiving hospital EMR knows exactly where each transaction begins and ends.