High-Speed SECS Message Services

SEMI E37 High-Speed SECS Message Services (HSMS) is the primary SEMI SECS/GEM transport protocol standard used. HSMS defines a TCP/IP based Ethernet connection used by GEM for host/equipment communication. It is intended as an alternative to SEMI E4 (SECS-I) for applications where higher speed communication is needed and the facilitated hardware setup is convenient. HSMS provides a means for independent manufacturers to produce implementations which can be connected and interoperate without requiring specific knowledge of one another. This is the transport protocol required in all 300mm fabs. HSMS-SS is a subsidiary standard for single session implementation of this standard for point-to-point communication between one host and one equipment. HSMS-SS provides a subset of HSMS, including the minimum set of services required for use as a direct SECS-I replacement. HSMS General Services, SEMI E37.2 (HSMS-GS), is also a subsidiary standard that focuses on use of HSMS in the cluster tool environment.

Download the complete white paper on the SECS/GEM standards.

SEMI E37 Background and Objectives

Initially, the primary equipment communication standard used by the semiconductor industry was the SEMI E4 SECS-I protocol. In the mid-1980s, a SEMI task force was created to develop a high-speed alternative. In 1990, SEMI E13, based on the General Motors Manufacturing Automation Protocol (MAP), was published. However, due to its limited use and the quick advancement of technology, a new task force was created in 1992 to re-address higher speed and throughput network communications. The primary objective of the high-speed equipment communication standard was the ability to operate on a variety of platforms in order to maximize adoption. The Transmission Control Protocol/ Internet Protocol (TCP/IP) was chosen as the protocol for this new standard because of its wide-spread use and availability. The High-Speed Message Services (HSMS) E37 Standard was published in July 1994.

HSMS Generic Services

The HSMS Standard defines message exchange procedures for using the TCP/IP network protocol.

  • Establishing a communication link between entities using a TCP/IP connection procedure
  • Developing and maintaining the protocol conventions necessary for exchanging SECS messages between entities
  • Sending and receiving data using TCP/IP 
  • Recognizing error conditions
  • Ending communications formally to confirm both parties no longer need the TCP/IP connection
  • Breaking the communications link logically without any physical disconnect from the network medium
  • Testing the communications link for the purpose of connection integrity
  • Rejecting connection attempts from incompatible subsidiary standards

In addition, the SEMI E37 standard describes special considerations, such as network timeouts, and handling multiple connections, which should be taken into account in a TCP/IP implementation.

Implement the HSMS E37 Standard With These Cimetrix Products


CIMConnect is an object-oriented software development kit for equipment suppliers to quickly develop host equipment communications interfaces. It makes extensive use of Active X/COM technology and is specifically designed to allow easy customization of the protocol and message format. The CIMConnect architecture allows equipment suppliers the emerging Internet-based communications of tomorrow as well as e-Diagnostics and CAMX. The current release supports the GEM, SECS-I, SECS-II, and HSMS standards. CIMConnect also supplies the tools to support the GEM300 SEMI standards. CIMConnect includes Cimetrix EquipmentTest™.

For more information on the CIMConnect product, please visit the CIMConnect Resources Page.