ACS Marvair CommStat 4

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Summary

Installation

Power Cable Connection

Explains connecting the grey power cable to a 24VDC or 48VDC source.

CommStat 4 Connection

Describes plugging the RJ11 cable into the CommStat 4 circuit board.

Powering On and Verification

Guides on turning on the power breaker and checking the red LED.

IP Address Configuration

Network and Sharing Center Access

Guides on accessing the Network and Sharing Center via Control Panel.

Local Area Connection Properties

Internet Protocol Version 4 (TCP;IPv4) Properties

Explains configuring the IP address, subnet mask, and default gateway.

Adapter Network Configuration Page

Describes accessing the adapter's configuration page via browser and setting IP/DHCP.

CommStat 4 Modbus Read Registers

CommStat 4 Modbus Write Registers

CommStat 4 Interface RJ11 Connector

Summary

Installation

Power Cable Connection

Explains connecting the grey power cable to a 24VDC or 48VDC source.

CommStat 4 Connection

Describes plugging the RJ11 cable into the CommStat 4 circuit board.

Powering On and Verification

Guides on turning on the power breaker and checking the red LED.

IP Address Configuration

Network and Sharing Center Access

Guides on accessing the Network and Sharing Center via Control Panel.

Local Area Connection Properties

Internet Protocol Version 4 (TCP;IPv4) Properties

Explains configuring the IP address, subnet mask, and default gateway.

Adapter Network Configuration Page

Describes accessing the adapter's configuration page via browser and setting IP/DHCP.

CommStat 4 Modbus Read Registers

CommStat 4 Modbus Write Registers

CommStat 4 Interface RJ11 Connector

The Marvair® CommStat™ 4 Modbus Interface Adapter is a self-contained device designed to provide an Ethernet or serial gateway for remote monitoring and control of Marvair CommStat™ 4 HVAC controllers. It allows an external host, such as a Network Operations Center (NOC), to read and write parameters to the CommStat 4 controller using either Modbus TCP or Modbus RTU communication protocols. This enables remote monitoring and control of HVAC units connected to the CommStat 4 controller. The adapter is compatible with CommStat 4 controllers running protocol version 3 or later, with software revision 67 or later.

Important Safety Information:

Always turn off electrical power at the breaker or fuse box before installation or maintenance to avoid hazardous or lethal line voltages.
Observe and comply with all applicable electrical and building codes and ordinances.
Installation and service should only be performed by qualified and experienced personnel.
Exercise common sense and be safety conscious.
The safety alert symbol (a triangle with an exclamation mark) indicates potential for personnel injury or equipment damage. Signal words like DANGER, WARNING, and CAUTION are used to denote the seriousness of the hazard.
- DANGER: Failure to comply will result in death or severe personal injury and/or property damage.
- WARNING: Failure to comply could result in death or severe personal injury and/or property damage.
- CAUTION: Failure to comply could result in minor personal injury and/or property damage.
IMPORTANT is used for helpful suggestions that improve installation, reliability, or operation.
Do not make power connections with power applied to the feed circuit, as this can cause electrical arcing and permanent damage to circuit boards. Always make electrical connections with the feed circuit breaker in the Off position and after verifying the absence of voltage with a meter.

Function Description:

The adapter acts as a bridge, translating communication between a remote host (using Modbus TCP/IP or Modbus RTU) and the CommStat 4 HVAC controller. This allows for comprehensive monitoring and control of HVAC system parameters from a centralized location.

Key Components Included:

Flange-mount enclosure containing the interface adapter.
15ft (457cm) two-conductor power cable.
15ft (457cm) RJ11 cable for connection to the CommStat 4 unit.
15ft (457cm) Cat5e cable for Modbus TCP connection to the external monitoring system.
15ft (457cm) Serial cable for Modbus RTU connection to the external monitoring system.

Installation Features:

Mounting: The adapter can be mounted at any convenient location within the shelter using its pre-drilled mounting ears. It is designed for direct installation on a shelter wall or within an equipment enclosure.
Location Restriction: The adapter must be installed inside the shelter and is not suitable for installation inside an HVAC unit or in locations exposed to external weather.
Cable Length: Supplied cables (Ethernet, serial, CommStat 4 communication, and power) are each 15ft (457cm) in length. The adapter should be mounted to ensure the total distance from end connection points, including conduit routing, does not exceed 15ft (457cm).
Power Connection: The adapter can be powered by 24VDC or 48VDC. The black wire is +24/48VDC, and the white wire is VDC RTN.
CommStat 4 Connection: An RJ11 connector on the flat, black CommStat 4 communications cable plugs into one of the two Master communications ports on the CommStat 4 circuit board. If two CommStat 4 controllers are present, one port might already be used for master/slave connection.
Power Verification: After connecting power, the red LED on the processor board should illuminate. If not, the power feed circuit breaker should be turned off, the black and white wires at the DC power source swapped, and the breaker turned back on.

Usage Features:

IP Address Configuration: The adapter has a default static IP address of 192.168.1.19. This can be re-configured using a laptop with Windows 7, 8, or 10. The laptop must be assigned a temporary static IP address within the same subnet (e.g., 192.168.1.100) to establish communication.
- Access the network configuration page by typing http://192.168.1.19 into an Internet browser (Internet Explorer, Chrome, Firefox, Safari).
- Users can select either DHCP or Static IP address configuration. For static configuration, IP Address, Subnet Mask, and Default Gateway fields can be set.
- Pressing the "Save" button reboots the adapter, and the new network configuration becomes active after 60 seconds.
Network Reset: If the adapter's network status is unknown, the IP address fields can be reset to the default 192.168.1.19. This is done by pressing the "Reset Network Settings" push button on the underside of the top right-hand corner of the main circuit board while power is applied. The adapter will restart and revert to the default IP address after approximately one minute.
Modbus Read Registers: The adapter supports Modbus TCP/IP read requests through port 502. A comprehensive list of read registers (40001-40068) is provided, detailing various CommStat 4 parameters such as firmware revision, protocol version, F/C setting, changeover days, set points (cool, heat, high building temp, low building temp), blower status, voltage input enable, anti-short cycle timer, stage differentials, blower off time delay, operational units, smoke auto reset, smoke relay, ECON mode, multiple sensors, Aux relays, excessive cycle, language, AC/HP system, master/slave status, password bytes, controller inputs/outputs, lockout statuses, current stage, and current temperature. Notes clarify bit-level interpretations for various status registers (e.g., smoke detection, hydrogen level, generator use, aux signals, voltage presence, lockout status, AC/economizer mode, outputting to Y/2/O/W/G/MAR/DCAMR, and high/low building temp lockouts).
Modbus Write Registers: The adapter supports Modbus TCP/IP write requests through port 502. A list of write registers (40101-40143) allows modification of CommStat 4 settings, including write control, F/C setting, changeover days, set points, blower status, voltage input enable, anti-short cycle timer, stage differentials, blower off time delay, operational units, smoke auto reset, smoke relay, ECON mode, multiple sensors, Aux relays, excessive cycle, language, AC/HP system, master/slave status, password bytes, and function code.
Parameter Update Process: Updating CommStat 4 parameters is controlled via register 40101. The sequence involves:
- 0 (Normal operation): Current parameters are copied to "new parameter values" registers each cycle.
- Remote Client Writes 1: Adapter stops copying current parameters, allowing the remote client to update selected parameters.
- Remote Client Writes 2: Instructs the adapter to write "new parameter values" to CommStat 4 at the next available cycle.
- Adapter Writes 3: Adapter confirms the write request and waits for write cycle completion.
- Adapter Writes 0: Adapter confirms completion of the write to CommStat 4.

Technical Specifications:

Electrical:
- Voltage: 24VDC to 60VDC (nominal 24VDC or 48VDC).
- Current: 1A typical.
Environmental:
- Temperature: -30°C (-22°F) to 70°C (158°F).
- Relative Humidity: 0% to 95%, non-condensing.
Mechanical:
- Dimensions: 10.00 inches x 6.00 inches x 3.00 inches (25.40 cm x 15.24 cm x 7.62 cm).
- Weight: 1.37 lbs (0.62 kg).
- Construction Material: POLYLAK® PA-765 ABS Thermoplastic (flammability rating UL94-5VA).
External Connections:
- Power Supply Terminal Block (2-position):
  - Black: V+ (Power Input)
  - White: COM (Power Return)
- Modbus RTU Interface Terminal Block (2-position):
  - Black: A (RS-485 RX/TX A)
  - White: B (RS-485 RX/TX B)
  - Serial Configuration: 9600, N, 8, 1.
- CommStat™ 4 Interface RJ11 Connector (6-pin):
  - Pin 1: NC
  - Pin 2: Ground
  - Pin 3: RS-485 RX/TX A
  - Pin 4: RS-485 RX/TX B
  - Pin 5: VCC
  - Pin 6: NC
- Ethernet RJ45 Connector (8-pin): Supports TIA/EIA T568B standard.
  - Pin 1: RD+
  - Pin 2: RD-
  - Pin 3: TD+
  - Pin 4: NC
  - Pin 5: NC
  - Pin 6: TD-
  - Pin 7: NC
  - Pin 8: NC