SKG Steam Humidifier
BACnet® Communication Module User Guide
2
Introduction & BACnet® Requirements
Introduction
This document provides a Users Guide for using the NEP PIC Communications Module for SKG Humidifiers
(NEPICSKG). This product provides a BACnet ® network interface between BACnet client devices and NEP
SKG Humidifier Series devices, specifically for SKG models. NEPICSKG uses the BACnet Master Slave/Token
Passing (MS/TP) protocol at the BACnet MAC layer.
This document assumes you’re familiar with BACnet and BACnet terminology.
BACnet® Requirements
Performance
The NEPICSKG uses a synchronous implementation for BACnet messages. Each BACnet confirmed service
request is answered as quickly as possible without using Reply Postponed. In particular, MS/TP implementation
performs within Tusage_delay of 15ms in order to assure Tusage_timeout values within 20ms.
Support for MS/TP
The NEPICSKG supports a Full Master Node state machine for MS/TP. Max_Master and the MS/TP MAC
address shall be configurable through WriteProperty service to the device object. A default MAC address of 254
shall be recognized when a configuration dip switch is set to configure mode. Two other dip switches shall
determine MS/TP baud rate 9600, 19200, 38400, and 76800. When in the configure mode WriteProperty
service requests may be directed to MAC address 254 using the wildcard Device instance (4194303
decimal/0x3FFFFF hex) as a means of configuring all other parameters for the device. Also, when in the
configuration mode the MS/TP MAC address and the Device Instance shall be configurable through the Unit’s
Keypad.
BIBB Support
The NEPICSKG generally behaves as a B-ASC type profile server. The following specific BIBBs are supported
per their relevant definitions in Annex K to BACnet:
DS-RP-B, DS-WP-B, DM-DDB-B, DM-DOB-B, DM-DCC-B
Object Support (in general)
The NEPICSKG supports a table-based fixed list of BACnet-visible values which appear as Present_Values of
various BACnet standard object types, in addition to a Device object.
Alarms
Although the NEPICSKG supports the ability to indicate various alarm conditions through value changes in
properties of several of its objects, it
does not
generate BACnet Event Notifications.
