4-20 mA)

Registers in Analogue I/O channel.

RegNo	Identifier	Memory type	Read Out	Type
0	AnalogIn	RAM Read Write	Decimal	Real
1	OutputSetpointPercentage	RAM Init EEPROM	Decimal	Real
2	OutputSetpointScaled	RAM Init EEPROM	Decimal	Real
3
4
5
6
7
8	Levels	RAM Init EEPROM	-------	Record
9	ChConfig	EEPROM RPW	-------	Record
10	FilterConstant	EEPROM RPW	Decimal	Real
11	Span	EEPROM RPW	Decimal	Real
12	Zeropoint	EEPROM RPW	Decimal	Real
13
14	Guid	PROM Read only	-------	String
15	ChError	RAM Read Write	Binary	Record

RegNo 0: AnalogIn

AnalogIn:

Real;

This variable holds the measurement result of the current input, as a scaled value in SI units, according to the contents of Span and Zeropoint. If the value should attempt to exceed 110% of fullscale, the contents of this register will be held at 110% of fullscale and the device will generate an error code. A similar situation occurs if the input signal attempts to drop below – 5%.

Act error in the P-NET response is set on access to AnalogIn if one of the following bit in ChError.Act is set: 0, 1, 4, 5, 7, 8, 9, 10, 11, 12, 15, 16, 17, 18, 19 or 20.

RegNo 1: OutputSetpointPercentage

OutputSetpointPercentage:

Real;

(* Factory setting = 0 *)

This variable holds the setpoint for the current output as a percentage (0-100%).

Writing to OutputSetpointPercentage automatically changes the value in OutputSetpointScaled, and vice versa.

Act error in the P-NET response is set on access to OutputSetpointPercentage if one of the following bits in ChError.Act is set: 0, 1, 4, 5, 12, 13, 14 or 16.

RegNo 2: OutputSetpointScaled

OutputSetpointScaled:

Real;

(* Factory setting = 0 *)

This variable holds the setpoint for the current output as a scaled value in SI units.

Writing to OutputSetpointScaled automatically changes the value in OutputSetpointPercentage.

Act error in the P-NET response is set on access to OutputSetpointPercentage if one of the following bits in ChError.Act is set: 0, 1, 4, 5, 12, 13, 14 or 16.

The Analogue input and the Current output share the same Span and Zeropoint.

RegNo 8: Levels

Record			(* Factory setting *)
	Level1:	Real;	(* 0 *)
	Level2:	Real;	(* 0 *)
	DeltaLevel:	Real;	(* 0 *)
End;

Levels can be used as a kind of limit switch; a notification and/or alarm can be connected. See also:

ChConfig.EnableNotification.

ChConfig.EnableFunctions.

RegNo 9: ChConfig

The ChConfig variable is a record of the following type:

Record			(* Factory setting *)
	EnableFunctions:	Bit8;	(* 0 *)
	SignalType:	Byte;	(* 0 *)
	EnableNotification:	Bit8;	(* 0 *)
	User:	Byte;	(* 0 *)
End;

EnableFunctions:

0: Simulation

1: Output_shutdown_by_watchdog_and_act_data_error

2: Act_data_error_on_AnalogIn_higher_than_Level1

3: Act_data_error_on_AnalogIn_lower_than_Level1

4: Act_data_error_on_AnalogIn_higher_than_Level2

5: Act_data_error_on_AnalogIn_lower_than_Level2

6: Inhibit_SignalHigh

7: Act_data_error_on_No_Load

Bit 0: Simulation.

When Simulation is set no measurement will be calculated, and it is possible for the user to insert any value in AnalogIn. If the channel is configured as an output, AnalogIn will follow the OutputSetpointScaled Setpoint value.

Bit 1: Output_shutdown_by_watchdog_and_act_data_error.

If the WDTimer reaches zero and the output shutdown is enabled, the current outputs will switch off and the “Act data error” is generated. See also WDTimer in Service channel.

The following enable bits enable “Act data error” in the P-NET response.

Bit 2: Act_data_error_on_AnalogIn_higher_than_Level1.

Bit 3: Act_data_error_on_AnalogIn_lower_than_Level1.

Bit 4: Act_data_error_on_AnalogIn_higher_than_Level2.

Bit 5: Act_data_error_on_AnalogIn_lower_than_Level2.

Bit 6: Inhibit_SignalHigh.

Selecting the InhibitSignalHigh bit ensures that even if an input signal exceeds 22 mA (20 mA + 10%), the SignalHigh bit in ChError will not be flagged.

This feature is included within modules using ProgramVersion 102 upward.

Bit 7: Act_data_error_on_No_load.

For a channel configured for 4-20 mA, a No Load Alarm can be generated when the current falls below 3 mA.

SignalType:
	0	=>	Current input 0-20 mA
	1	=>	Current input 4-20 mA
	2	=>	Current output 0-20 mA, with current input read-back.
	3	=>	Current output 4-20 mA, with current input read-back.
	9	=>	Channel disabled

EnableNotification:

Notification can be enabled in the following cases:

0: Change_in_ChError.Act

1: Output_shutdown_on_watchdog

2: Increasing_AnalogIn_crossing_Level1

3: Decreasing_AnalogIn_crossing_Level1

4: Increasing_AnalogIn_crossing_Level2

5: Decreasing_AnalogIn_crossing_Level2

6: AnalogIn_changed_Delta_level

7: No_Load

Bit 0: Change_in_ChError.Act.

Bit 1: Output_shutdown_by_watchdog

If the WDTimer reaches zero and output shutdown is enabled, the current outputs will switch off and the Output_shutdown_by_watchdog notification is generated. See also WDTimer in Service channel.

Bit 2: Increasing_AnalogIn_crossing_Level1.

Bit 3: Decreasing_AnalogIn_crossing_Level1.

Bit 4: Increasing_AnalogIn_crossing_Level2.

Bit 5: Decreasing_AnalogIn_crossing_Level2.

Bit 6: AnalogIn_changed_Delta_level

Enable notification on |AnalogIn – Old AnalogIn| > Levels.DeltaLevel. AnalogIn is copied to Old AnalogIn when Notification is set.

Bit 7: No_Load

For a channel configured for 4-20 mA, a No Load notification can be generated when the current falls below 3 mA and No Load error is enabled.

A bit in the Notification register in the Service Channel will be set if the condition described for any bit that is set in this EnableNotification field has been met. The Notification bit number in the Service Channel register will correspond with the channel number that detected the condition.

RegNo 10: FilterConstant

FilterConstant:

Real;

(* Factory setting = 0 *)

This variable selects a time constant for the input filter. The filter time constant defines that for a stepped change at the input terminals, the measured value (AnalogIn), will have changed by 63% of its target value, at the end of the specified time period.

Only FilterConstants > 3 and < 50 sec will activate the filter.

RegNo 11: Span

Span:

Real;

(* Factory setting = 20 *)

The span for the connected transmitter must be inserted in this variable.

RegNo 12: Zeropoint

Zeropoint:

Real;

(* Factory setting = 0 *)

The resultant measured value expected in AnalogIn when the input signal is at its minimum (0/4 mA), should be placed in the Zeropoint variable.

RegNo 14: Guid

Each channel type in an interface device consists of a unique Guid.

Guid:

String[22];

(*"xxxxxxxxxxxxxxxxxxxxxx"*)

RegNo 15: ChError

ChError:
Record
	His: Bit24;
	Act: Bit24;
End;

There are two sets of error bits, actual and historical. The actual error bits reflect the current situation and will automatically follow any change.

The historical error bits reflect the history and have the purpose of holding sporadic errors. The historical error bits are set together with the corresponding actual bits. They remain set after a read, so each individual bit must be cleared by setting it to false. Only the bits where the corresponding actual bit is false can be cleared. See summary for how ChError.His can be cleared in particular M36 slave modules.

The “His data error” bit in the P-NET response is set if any historical bit is true.

The “Act data error” bit in the P-NET response is reflecting the validity of the data in the response. Overload, electrical error or an error in other registers involved in calculating the result gives “Act data error”.

0: Program_storage_fault

1: RAM_storage_fault

2: InternalReset

3: ExternalReset

4: SignalHigh

5: SignalLow

7: Internal_error

8: AnalogIn_higher_than_Level1

9: AnalogIn_lower_than_Level1

10: AnalogIn_higher_than_Level2

11: AnalogIn_lower_than_Level2

12: No_Load

13: Output_shutdown_on_watchdog

14: EEPROM_error_in_Setpoint

15: EEPROM_error_in_Levels

16: EEPROM_error_in_ChConfig

17: EEPROM_error_in_FilterConstant

18: EEPROM_error_in_Span

19: EEPROM_error_in_Zeropoint

20: EEPROM_error_in_Internal_variable

21:

22:

23:

The following two bits will cause Act error In the P-NET response on access to all

variables.

Bit 0 Program_storage_fault is set TRUE if the self-test finds an error in the program memory.

Bit 1 RAM_storage_fault is set TRUE if the self-test finds an error in the data memory (RAM).

Bit 2 InternalReset is set TRUE if a reset is caused by a power failure, or if the power has been disconnected (only a His error).

Bit 3 ExternalReset is set TRUE if a reset is caused by writing 255 to Reset, via P‑NET (only a His error).

Bit 4: SignalHigh is set if the input signal exceeds 20 mA by more than 10% (22 mA).

Bit 5: SignalLow is set if the input signal falls below 0 mA by more than 5% (-1 mA).

Bit 7: An internal_error is indicated. If the device continues to indicate internal error after a reset, the device is likely to require repair.

Bit 8: AnalogIn_higher_than_Level1.

Bit 9: AnalogIn_lower_than_Level1.

Bit 10: AnalogIn_higher_than_Level2.

Bit 11: AnalogIn_lower_than_Level2.

Bit 12: No_Load is set if the channel is configured for 4-20 mA and the input signal falls below 3 mA.

Bit 13: Output_shutdown_by_watchdog is set if the channel is configured as output and WDTimer reaches zero. See also WDTimer in Service channel.

The following bits are set TRUE if the self-test finds an error in the data memory (EEPROM) for the variable. EEPROM fault is only set at power-up. If the corresponding variable is accessed, Act error in the P-NET response is set.

This error can occur if the power disappears when writing to EEPROM, so a rewrite to the

variable could possibly solve the problem.

Bit 14: EEPROM_error_in_Setpoint.

Bit 15: EEPROM_error_in_Levels.

Bit 16: EEPROM_error_in_ChConfig.

Bit 17: EEPROM_error_in_FilterConstant.

Bit 18: EEPROM_error_in_Span.

Bit 19: EEPROM_error_in_Zeropoint.

The following bit is set TRUE if the self-test finds an error in the data memory (EEPROM)

for the variable. EEPROM fault is only set at power-up.

Bit 20: EEPROM_error_in_Internal_calibration_variable.