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Overview

Atom supports the following ModbusTCP operations:

  • Read Holding Registers (Function code 3)
  • Write Single Holding Register (Function code 6)
  • Write single coil/command (Function code 5)
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ModbusTCP is always available and running, even if you're using Profinet or EtherNet/IP. ModbusTCP exposes more parameters than the other fieldbus protocols and may be useful for more advanced configuration.

Control Panel Communication Settings​

Control Panel Communication Settings

Some communication settings can be configured in the Communication tab in Control Panel.

  • Section 1: TCP/IP settings
    • IP Address Configuration
      • Static: Use the IP address, subnet mask, and gateway specified below.
      • DHCP: Use DHCP to obtain an IP address.
    • IP Address Setting: The IP address of the ATOM controller.
    • IP Address Monitor: The current IP address of the ATOM controller.
    • Subnet Mask: The subnet mask of the ATOM controller.
    • Gateway: The gateway address for the ATOM controller.
  • Section 2: Network Timeout
    • The EtherNet/IP heartbeat timeout (Encapsulation Inactivity Timeout) in seconds.
    • You can configure a network timeout action to perform when the device loses communication with the PLC:
      • None: Do nothing
      • STOP, fault shutdown: STOP the controller, disabling output
      • Use network timeout setpoint: Configure an alternative setpoint to use when the controller loses communication with the PLC.
  • Section 3: Ethernet status
    • Indicates the status of both RJ45 ports, IP address configuration, conflict detection, and any other errors with the EtherNet/IP connection.
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Control Panel and PLC software​

These settings are synchronized with your PLC environment. You do not have to use Control Panel to change these settings - you can stay in your PLC software. Control Panel merely provides them as an altnerative way to configure ATOM's EtherNet/IP settings.

You can use Control Panel simultaneously with your PLC software without issues.

warning

IP Address Conflict Detection​

ATOM uses IP Address Conflict Detection to detect IP address conflicts on the network. If ATOM detects another device using the same IP address, it will disable all network communication until the conflict is resolved.

Please ensure all devices on the network are assigned unique a IP address.

Hardware considerations​

warning

Daisy chaining​

As ATOM has two RJ45 ports, it can be easily daisy-chained. When daisy-chaining ATOM, take care to avoid a loop in the network. In some loop configurations, ATOM is susceptible to network broadcast storms, which can cause the controller to become unresponsive. If you are daisy-chaining ATOM, ensure that the network is loop-free.

ATOM works with both unmanaged and managed switches. We recommend a managed switch for larger networks to give you more control over the network topology.

Registers​

Register #NameDefaultMinMaxScaleUnitRead/WriteNotes
2Feedback Type112Read/Write
3Firing Mode516Read/Write
4Slew Rate101100Read/WriteSingle phase only
5Control Loop101Read/Write
6Full Scale Voltage480.010.0600.010vRead/Write
7Full Scale Current80.02.0100.010ARead/Write
8Voltage Limit70010700vRead/Write
9Current Limit84.01.0105.010ARead/Write
10Current Trip24052451ARead/Write
11Analog Setpoint Zero threshold000Read/Write
12Analog Setpoint Type012Read/Write
13Analog Setpoint Low Cmd0.00-5.0025.00100v, maRead/Write
14Analog Setpoint Low Out0.000.00125.00100%Read/Write
15Analog Setpoint High Cmd0.00-5.0025.00100v,maRead/Write
16Analog Setpoint High Out0.000.00125.00100%Read/Write
17Partial Load Fault Enable001Read/Write
18PLF Tolerance8.00.0100.010%Read/Write
19Partial Load Fault Resistance8.000.10655.35100ohmRead/Write
20PLF Alarm Delay time101120secRead/Write
21Relay Alarm Mask384065535Read/Write
22Shorted SCR detect enable002Read/Write
23Open Load detect enable001Read/Write
24Digital Setpoint 1 (EEPROM)0010000Read/Write
25Digital Setpoint 2 (RAM) 10010000Read/Write
26Digital RUN Enable001Read/Write
27Setpoint Select222Read/Write
28Digital RUN Enable power-up default001Read/Write
29PLF Teach Enable001Read/Write
30Communications Heartbeat Time0065535Read/Write
31Network Timeout Action002Read/Write
32Network Timeout Setpoint0010000Read/Write
33IP Address Configuration method101Read/Write
34IP Address, OCTET 11920255Read/Write
35IP Address, OCTET 21680255Read/Write
36IP Address, OCTET 3710255Read/Write
37IP Address, OCTET 42500255Read/Write
38Subnet Mask, OCTET 12550255Read/Write
39Subnet Mask, OCTET 22550255Read/Write
40Subnet Mask, OCTET 32550255Read/Write
41Subnet Mask, OCTET 400255Read/Write
42Gateway IP Address, OCTET 11920255Read/Write
43Gateway IP Address, OCTET 21680255Read/Write
44Gateway IP Address, OCTET 300255Read/Write
45Gateway IP Address, OCTET 41000255Read/Write
46Relay Normal State001secRead/Write
Format
201Active SetpointXRead
202Analog Setpoint %SXXX.X10%Read
203Analog Setpoint CmdSXXX.X10V,ARead
204Analog Setpoint SignalSXX.XX10v,maRead
205Inhibit Alarm StatusXXXXXXXXReadSee bitfield
206Controller StatusXReadSee values
207AC Line FrequencyXX.X10HzRead
208Line VoltageXXX.X10VRead
209Load VoltageXXX.X10VRead
210Load CurrentXXX.X10ARead
211Load ResistanceXXXX.X10ohmRead
212Heatsink tempXXX.X10CRead
213Controller StateXReadSee values
214Output Duty Cycle %XXX.X10%Read
215Setpoint ReferenceXXX.X10V,ARead
216FeedbackXXX.X10V,ARead
217Control Loop ErrorSXXX.X10V,ARead
218Warning Alarm StatusXXXXXXXX100ReadSee bitfield
219Partial Load Fault Target ResXXX.XX100ohmRead
220Partial Load Fault ResistanceXXX.XX100ohmRead
221PLF Resistance DeviationSXXX.X10%Read
222Partial Load Fault StatusXXXXXXXXRead
310In Service Time HIXXXXXXXXXXRead
311In Service Time LORead
312Processor TemperatureXXX.X10CRead
330EE Calibration bitsXXXXRead
331Calibration ADC bits InXXXXRead
332Firmware IDXXXXXRead
333Firmware RevisionXX.XX100Read
334Minor RevisionXXRead
335Feedback Read statusXReadSee bitfield
336Misc StatusXXXXXXXXReadSee bitfield
337EEPROM StatusXXXXXXXXXXXXXXXXReadSee bitfield
338AC Line StatusXXXXXXXXReadSee bitfield
339Load StatusXXXXXXXXRead
340Error LatchXXXXXXXXReadSee bitfield
341Ethernet statusXXXXXXXXXXXXXXXXReadSee bitfield
342Network Heartbeat TimerXXXXXRead
343IP Address in use, OCTET 1XXXRead
344IP Address in use, OCTET 2XXXRead
345IP Address in use, OCTET 3XXXRead
346IP Address in use, OCTET 4XXXRead

Additional parameter descriptions​

Inhibit Alarm Status​

Inhibit alarm status is a 8-bit bitfield:

76543210
ReservedReservedReservedReservedFeedback LossOver TemperatureOver Current TripAC Line Lock Loss

If any bit is set to 1, the controller will not be allowed to run.

Warning Alarm Status​

Warning alarm status is a 8-bit bitfield:

76543210
ReservedReservedHigh temperatureShorted SCROpen LoadPartial Load FaultCurrent LimitVoltage Limit

Warning alarms are not considered critical and will not prevent the controller from running.

Feedback Read Status​

Feedback status is a 8-bit bitfield:

76543210
ReservedReservedReservedReservedReservedReservedReservedTimeout

Indicates whether the controller has acquired feedback on the line. If any bit is set to 1, then the controller has lost feedback.

AC Line Status​

AC Line status is a 8-bit bitfield:

76543210
ReservedReservedSync-Locked (to AC Line)Pre-Lock 2Pre-Lock 1ReservedAC Line B OKAC Line A OK

Bits 5 must be set to 1 before the controller can provide power to the load.

Load Status​

Load status is a 8-bit bitfield:

76543210
ReservedReservedReservedOpen LoadReservedReservedReservedShorted SCR

Controller Status​

Controller status is one of:

ValueDescription
0Disabled
1Initialization
2Normal, operating
3Calibration
4Diagnostic

Controller State​

Controller state is one of:

ValueStateDescription
0STOPThe state the controller is in when AC Line voltage is not present.
1RUNThe state the controller is in when AC Line voltage is present and the controller is synchronized to the AC line.
2FAULTA latching state of output shutdown caused by over current or over temperature alarms. A power cycle or processor reset is required to clear this state.
3FAULT RESETUsed as a temporary state to transition from FAULT to RUN once again.

EEPROM Status​

EEPROM status is an 16-bit bitfield. EEPROM is used to store controller configuration and calibration data. Any errors in EEPROM may indicate that the firmware is corrupted.

BitDescription
0EEPROM Initialization
1SP Table Error
2MFG CP Table Error
3Calibration Table Error
4Reserved
5Reserved
6Backup Calibration Table Error
7Bottom Board Calibration Table Error
8SP Definition Table needs updating
9Bottom Board Calibration Backup Error
10Reserved
11Reserved
12EEPROM is write protected
13Reserved
14Reserved
15Feedback Calibration Table has changed, store to EEPROM

Error Latch​

Error latch is a 8-bit bitfield:

76543210
ReservedReservedReservedFeedback lossSCR timing lossLine Frequency failurePhase loss or missing cycleLine Lock Loss

Error latch is provided as a diagnostic troubleshooting aid.

Miscellaneous Status​

Miscellaneous status is an 8-bit bitfield:

76543210
ReservedInitialization in progressReservedReservedWaiting for ENTER key during initializationReservedUSB PoweredReserved

Data types​

All Modbus registers are 2-bytes (WORD).

Registers may be an unsigned integer (most commonly), bitfield, integer, bool, or decimal.

Most of these are straightforward. Decimals are stored as integers with a scale in our controllers.

The Scale column indicates how much you should divide the value by when reading it, and how much you should multiply it by when writing it.

Commands​

CMD #NameDescription
6Factory resetReset to factory settings
13Reset parameterResets user parameters to defaults
24Store to EEPOMSaves all parameters to permanent storage
198IdentifyFlashes LEDs on controller
248ResetEffectively restarts the controller

Miscallaneous​

Important

You may notice that ModbusTCP parameter numbers are one less than the same parameters in other ATOM fieldbus profiles. This is because ModbusTCP uses zero-based addressing and subtracts 1 from all register numbers. The table above lists the actual register numbers you should use in your PLC project.