This chapter provides a brief overview of the Siemens Middleware Services for the Integrated Buildings (MSIBTM) application.
What is MSIB?
MSIB is middleware primarily targeted to meet diverse integration needs at the IP and web service level. MSIB supports real time collaboration of local Building Automation System (BAS) data and web service data. MSIB consists of the following two components:
- Windows Service: The MSIB Windows Service runs in the background and continuously processes services for multiple virtual nodes.
- User Interface: A browser-based user interface provides for the configuration and maintenance of the virtual MSIB nodes. These virtual MSIB nodes are a digital representation within MSIB of a field panel and all of its associated points.
How MSIB works
MSIB runs as a Windows Service consisting of at least one and potentially many virtual nodes which host one or more service processes. MSIB uses virtual nodes to collect data from a source to serve those nodes to an assigned destination.
MSIB nodes
MSIB runs as a service providing collaboration of data between the BAS and other systems or services.
As an example, the following describes how MSIB would function while serving BACnet IP data.
To a data consumer, each MSIB node is a digital representation of a physical field panel and all of its associated points. The consumer sees data as if it is physically connected to field panels controlling mechanical equipment, but in fact the consumer is seeing only virtual copies.
This allows consumers to retrieve data however they choose, while having little impact or risk to the physical panels and systems. MSIB contains as many of these virtual nodes as necessary to model the physical system. The power of MSIB is this ability to scale to immense size, as needed to digitally represent the physical world in a building, campus, or even a large enterprise.
The maximum number of points allowed in a virtual node varies because it is dependent on the user-configured variables of polling seconds and the number of milliseconds between each individual point. For how to configure this, see the creating and configuring nodes chapter for the MSIB service you plan to use. As an example, with a 15-minute polling interval and allowing a slight safety margin for possible retries, the maximum points per node would be:
Separation milliseconds | Maximum points |
|---|---|
300* | 2700 |
400* | 2025 |
500* | 1620 |
600 | 1350 |
700 | 1156 |
800 | 1012 |
900 | 900 |
1000 | 810 |
1250 | 648 |
1500 | 540 |
2000 | 405 |
*BACnet requires at least 600 millisecond separation | |
In the special case of MSTP ALN devices connected to a field panel as a router, the network baud rate affects the settings. In this situation, recommended settings for separation and maximum points are as follows:
MSTP ALN baud rate | Polling interval (sec) | Recommended minimum separation interval (ms) | Equivalent max # of points |
|---|---|---|---|
9600 | 900 | 1000 | 810 |
19,200 | 900 | 750 | 1080 |
38,400 | 900 | 600* | 1350 |
76,800 | 900 | 600* | 1350 |
115,200 | 900 | 600* | 1350 |
*BACnet requires at least 600 millisecond separation | |||
Compatibility
Modbus
MSIB supports the following Modbus TCP data:
Category | Supported data types |
Binary | Coils (binary outputs) |
Binary (binary inputs) | |
|
|
Analog inputs | Analog inputs 16 bit unsigned |
Analog input 16 bit signed | |
Analog input 32 bit unsigned | |
Analog input 32 bit signed | |
Analog input 32 bit float | |
Analog input 64 bit float | |
Analog input 8 bit unsigned (half registers) | |
Analog input 8 bit signed (half registers) | |
Analog input 16 bit as 16 digital points | |
|
|
Holding registers | Holding registers 16 bit unsigned |
Holding registers 16 bit signed | |
Holding registers 32 bit unsigned | |
Holding registers 32 bit signed | |
Holding registers 32 bit float | |
Holding registers 64 bit float | |
Holding registers 8 bit unsigned (half registers) | |
Holding registers 8 bit signed (half registers) | |
Holding registers 16 bit as 16 digital points |
See the Siemens document titled MSIB Modbus Application Guide for more information when working with Modbus.
SNMP
MSIB supports SNMP versions 1, 2 and 3.
BACnet
MSIB supports the following point types:
Abbreviation | Object type |
|---|---|
AI | analog_input |
AO | analog_output |
AV | analog_value |
BI | binary_input |
BO | binary_output |
BV | binary_value |
MI | multi_state_input |
MO | multi_state_output |
MV | multi_state_value |
Currently, MSIB does not support all special characters in point or device names. MSIB supports a subset of Unicode character sets encoded as UTF-8.
If special characters are used, MSIB may reject the information and a node cannot be created.