Role of OPC in GM Powertrain Manufacturing

1
Role of OPC in GM Powertrain Manufacturing

• Hamid Ghadamabadi
• Advanced Manufacturing Control Systems
• General Motors Powertrain

2
OPC and GMPT requirements

• OPC provides a set of standard interfaces to link
  applications for the the purpose of data sharing.
• The interfaces are published in specifications
  published by OPC Foundation.
• Applications operate in a client server
  environment.
• Useful features
• Grouping of data and assigning various update
  intervals.
• Provides data value, data time stamps and
  quality.
• Provides data in polled and unsolicited modes.

3
OPC and GMPT requirements

• GMPT interface requirements for controls
  applications
• Capable of handling real-time peer to peer
  (controller to controller) communication when the
  number of controllers is low (less than ten) and
  the data size is small ( a few Bytes).
• Capable of handling non-real-time controller to
  supervisory system communication when the number
  of controllers are large (100 units) and the data
  size is large ( greater than 1000 Bytes)

4
GMPT Manufacturing Network Architecture
Profibus-DP
Central Data Server with Non-standard API
MMS on Ethernet
Information System
Monitoring System
ISA Profibus Card
TCP/IP
Ethernet HUB
Process Monitoring
Plant Floor
Controls/HMI PC with Non-standard API
Controls/HMI PC with Non-standard API
Controls/HMI PC with Non-standard API
Controls/HMI PC with Non-standard API
Controls/HMI PC with Non-standard API
Profibus I/O
Profibus I/O
Profibus I/O
Profibus I/O
Profibus I/O
5
Data Flow Structure from Profibus Devices to
Applications in Current GMPT Programs
HMI Application
Non-standard Vendor Specific API
Controls Application
Non-standard Vendor Specific API
Validated Profibus Data
Profibus Card RAM
Windows NT
Profibus I/O Device
6
Manufacturing Network Based on OPC/DCOM
Profibus-DP
Central Data Server with OPC API
DCOM on Ethernet
Information System
Monitoring System
ISA Profibus Card
ISA Profibus Card
PCI Profibus Card
Ethernet HUB
DCOM Server NT Server
Process Monitoring
Plant Floor
Local HUB
Controls/HMI PC with OPC API NT Server
Controls/HMI PC with OPC API
Controls/HMI PC with OPC API
Controls/HMI PC
Controls/HMI PC with OPC API
Profibus I/O
Profibus I/O
Profibus I/O
Profibus I/O
Profibus I/O
7
A Proposed New Data Flow Structure from Profibus
Devices to Applications Based on OPC Interfaces
OPC Client (non-real-time)
HMI Application
OPC Remote Server
OPC
OPC Client (real-time)
Controls Application
OPC Local/Remote Server
OPC
Validated Profibus Data
OPC In-Process Server
Profibus Card RAM
Windows NT
Profibus I/O Device
8
OPC/DCOM Network Topology for SOI Data Server
OPC Clients
OPC Clients
OPC Clients
NT Workstation
NT Workstation
NT Workstation
DCOM over TCP/IP
Ethernet HUB
9
OPC/DCOM Network Topology for SOI Data Server

• The NT server is a DCOM server with necessary
  components to run DCOM services for a client.
• The server is set up to be part of NT domain
  which allows a central point of authentication
  for use with client configurations.
• OPC server types
• In-process
• Server code is implemented in DLL.
• Server and client are part of the same process.
• Suitable for deterministic and fast data transfer
  between a server and a client.
• Local
• A Local server is implemented as an EXE.
• Server and client are two separate processes
  running on the same machine.
• Remote
• Server and client are two separate processes on
  two different machines.
• DCOM provides the data transport mechanism.

10
Measured Mean and Standard Deviation Update Rate
of An Integer Value In a Client Application
Server Update rate10ms Client Update Rate 10
ms
11
Measured Mean and Standard Deviation Update Rate
of An Integer Value In a Client Application

• Typical controller scan time in GMPT applications
  is 20 ms.
• The size of data for controller peer to peer
  communication for most applications is small, a
  few words.
• Dedicating an Ethernet network for the purpose of
  peer to peer communication reduces delays due to
  network traffic.

12
Benefits and Issues

• OPC allows multi-vendor applications to share
  data through standard interfaces.
• Reduced validation time
• Rapid application development
• Server start up problems
• validating and registering items
• APIs for deterministic peer to peer
  communication.
• APIs for data transfer between HMI and controls.
  applications