IEC 61804-2:2004

INTERNATIONAL IEC
STANDARD 61804-2
First edition
2004-05
Function blocks (FB) for process control –
Part 2:
Specification of FB concept and Electronic
Device Description Language (EDDL)

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INTERNATIONAL IEC
STANDARD 61804-2
First edition
2004-05
Function blocks (FB) for process control –
Part 2:
Specification of FB concept and Electronic
Device Description Language (EDDL)

© IEC 2004 – Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale
XH
International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 61804-2 © IEC:2004(E)
CONTENTS
FOREWORD.22

INTRODUCTION.24

1 Scope .25

2 Normative references .26

3 Terms and definitions, abbreviated terms and acronyms, and conventions for
lexical structures .27

3.1 Terms and definitions .27

3.2 Abbreviated terms and acronyms .34
3.3 Conventions for lexical structures .34
4 General Function Block (FB) definition and EDD model .36
4.1 Device structure (device model).36
4.1.1 Device model description .36
4.1.2 FB type.40
4.1.3 FB execution.41
4.1.4 Reference between IEC/PAS 61499-1, IEC/PAS 61499-2 and IEC
61804 models .42
4.1.5 UML specification of the device model.42
4.1.6 Classification of the algorithms.44
4.1.7 Algorithm description .45
4.1.8 Input and output variables and parameter definition .45
4.1.9 Choice of variables and parameters.46
4.1.10 Mode, Status and Diagnosis.46
4.2 Block combinations.46
4.2.1 Measurement channel .46
4.2.2 Actuation channel .47
4.2.3 Application.48
4.3 EDD and EDDL model .49
4.3.1 Overview of EDD and EDDL .49
4.3.2 EDD architecture .49
4.3.3 Concepts of EDD .49
4.3.4 Principles of the EDD development process.49
4.3.5 Interrelations between the lexical structure and formal definitions .50
4.3.6 Builtins .51

4.3.7 Profiles .51
5 Detailed block definition.51
5.1 General.51
5.2 Application FBs .51
5.2.1 Analog Input FB .51
5.2.2 Analog Output FB .53
5.2.3 Discrete Input FB .54
5.2.4 On/Off Actuation (Output) FB Discrete Output FB .56
5.2.5 Calculation FB .57
5.2.6 Control FB .58
5.3 Component FBs.59
5.4 Technology Block .59
5.4.1 Temperature Technology Block .59

61804-2 © IEC:2004(E) – 3 –
5.4.2 Pressure Technology Block .62

5.4.3 Modulating Actuation Technology Block.64

5.4.4 On/Off Actuation Technology Block .66

5.5 Device (Resource) Block .68

5.5.1 Identification .68

5.5.2 Device state.69

5.5.3 Message.71

5.5.4 Initialization .71

5.6 Algorithms common to all blocks .71

5.6.1 Data Input/Data Output status .71

5.6.2 Validity .71
5.6.3 Restart Initialization .71
5.6.4 Fail-safe .72
5.6.5 Remote Cascade Initialization .72
6 FB Environment.73
7 Mapping to System Management .73
8 Mapping to Communication.73
9 Electronic Device Description Language .75
9.1 Overview.75
9.1.1 EDDL features .75
9.1.2 Syntax representation .75
9.1.3 EDD language elements.75
9.1.4 Basic construction elements .75
9.1.5 Common attributes.81
9.1.6 Special elements .81
9.1.7 Rules for instances .81
9.1.8 Rules for list of VARIABLEs .81
9.2 EDD identification information.82
9.2.1 General structure .82
9.2.2 Specific attributes .82
9.3 BLOCK.84
9.3.1 BLOCK_A .84
9.3.2 BLOCK_B .88
9.4 COLLECTION.90
9.4.1 General structure .90
9.4.2 Specific attributes - item-type .90
9.5 COMMAND .91
9.5.1 General structure .91
9.5.2 Specific attributes .92
9.6 CONNECTION .96
9.6.1 General structure .96
9.6.2 Specific attribute - APPINSTANCE .96
9.7 DOMAIN.97
9.7.1 General structure .97
9.7.2 Specific attribute - HANDLING.97
9.8 EDIT_DISPLAY .98
9.8.1 General structure .98
9.8.2 Specific attributes .98

– 4 – 61804-2 © IEC:2004(E)
9.9 IMPORT .100

9.9.1 General structure .100

9.9.2 Specific attributes – attribute-redefinition.102

9.10 LIKE .108

9.11 MENU.108

9.11.1 General structure .108

9.11.2 Specific attributes .109

9.11.3 Sequence diagrams for actions .114

9.12 METHOD .118

9.12.1 General structure .118

9.12.2 Specific attributes .118
9.13 PROGRAM .119
9.13.1 General structure .119
9.13.2 Specific attributes - ARGUMENT .119
9.14 RECORD .120
9.15 REFERENCE_ARRAY.120
9.15.1 General structure .120
9.15.2 Specific attributes - ELEMENTS .121
9.16 Relations .121
9.16.1 General structure .121
9.16.2 REFRESH.121
9.16.3 UNIT.122
9.16.4 WRITE_AS_ONE .122
9.17 RESPONSE_CODES .122
9.18 VALUE_ARRAY .123
9.18.1 General structure .123
9.18.2 Specific attributes .123
9.19 VARIABLE .124
9.19.1 General structure .124
9.19.2 Specific attributes .125
9.20 VARIABLE_LIST .138
9.21 Common attributes.138
9.21.1 DEFINITION .138
9.21.2 HELP.139
9.21.3 LABEL .139

9.21.4 MEMBERS.139
9.21.5 RESPONSE_CODES .140
9.22 Output redirection (OPEN and CLOSE) .141
9.23 Conditional expression.141
9.24 Referencing .142
9.24.1 Referencing an EDD instance.142
9.24.2 Referencing members of a RECORD .142
9.24.3 Referencing elements of a VALUE_ARRAY .143
9.24.4 Referencing members of a COLLECTION .143
9.24.5 Referencing elements of a REFERENCE_ARRAY.144
9.24.6 Referencing members of a VARIABLE_LISTS.144
9.24.7 Referencing elements of BLOCK_A PARAMETERS .145
9.24.8 Referencing elements of BLOCK_A PARAMETER_LISTS .145
9.24.9 Referencing BLOCK_A CHARACTERISTICS .146

61804-2 © IEC:2004(E) – 5 –
9.25 Strings.146

9.25.1 Specifying a string as a string literal .146

9.25.2 Specifying a string as a string variable .146

9.25.3 Specifying a string as an enumeration value .146

9.25.4 Specifying a string as a dictionary reference.147

9.25.5 Referencing HELP and LABEL attributes of EDD instances.147

9.25.6 String operations.147

9.25.7 Prompt String Formats .148

9.26 Expression.148

9.26.2 Primary expressions.148

9.26.3 Unary expressions .150
9.26.4 Binary expressions.150
9.27 Text dictionary .153
10 Conformance statement.154
Annex A (informative) Parameter description .155
Annex B (normative) IEC 61804 Conformance Declaration.160
Annex C (normative) EDDL Formal Definition .161
C.1 EDDL Preprocessor.161
C.1.1 General structure .161
C.1.2 Directives .161
C.1.3 Predefined macros.164
C.1.4 NEWLINE characters .164
C.1.5 Comments .164
C.2 Conventions .164
C.2.1 Integer constants .164
C.2.2 Floating point constants .165
C.2.3 String literals .165
C.2.4 Using language codes in string constants .166
C.3 Operators.166
C.4 Keywords .167
C.5 Terminals .169
C.6 letter (letter|digit|_)*Formal EDDL syntax .169
C.6.1 General .169
C.6.2 EDD identification information .169

C.6.3 BLOCK_A and BLOCK_B .171
C.6.4 COLLECTION .173
C.6.5 COMMAND .173
C.6.6 CONNECTION .177
C.6.7 DOMAIN .177
C.6.8 EDIT_DISPLAY.178
C.6.9 IMPORT .179
C.6.10 LIKE .180
C.6.11 MENU.182
C.6.12 METHOD .185
C.6.13 PROGRAM .185
C.6.14 RECORDS.186
C.6.15 REFERENCE_ARRAY.186
C.6.16 Relations .187

– 6 – 61804-2 © IEC:2004(E)
C.6.17 RESPONSE_CODES .188

C.6.18 VALUE_ARRAY .189

C.6.19 VARIABLE .189

C.6.20 VARIABLE_LIST .197

C.6.21 Common attributes.197

C.6.22 OPEN, CLOSE.199

C.6.23 Expression.199

C.6.24 C-Grammer.201

C.6.25 Redefinition .204

C.6.26 References .216

Annex D (normative) EDDL Builtin Library .218
D.1 General.218
D.2 Conventions for Builtin descriptions .218
D.3 Builtin abort.218
D.4 Builtin abort_on_all_comm_errors.219
D.5 Builtin ABORT_ON_ALL_COMM_STATUS .219
D.6 Builtin ABORT_ON_ALL_DEVICE_STATUS .220
D.7 Builtin ABORT_ON_ALL_RESPONSE_CODES .220
D.8 Builtin abort_on_all_response_codes .221
D.9 Builtin abort_on_comm_error .221
D.10 Builtin ABORT_ON_COMM_ERROR .222
D.11 Builtin ABORT_ON_COMM_STATUS.222
D.12 Builtin ABORT_ON_DEVICE_STATUS.223
D.13 Builtin ABORT_ON_NO_DEVICE .223
D.14 Builtin ABORT_ON_RESPONSE_CODE .224
D.15 Builtin abort_on_response_code .225
D.16 Builtin ACKNOWLEDGE .225
D.17 Builtin acknowledge.225
D.18 Builtin add_abort_method (version A) .226
D.19 Builtin add_abort_method (version B) .226
D.20 Builtin assign.227
D.21 Builtin assign_double.227

D.22 Builtin assign_float .228
D.23 Builtin assign_int .228
D.24 Builtin assign_var .228
D.25 Builtin atof.229
D.26 Builtin atoi.229
D.27 Builtin dassign.229
D.28 Builtin Date_to_DayOfMonth.230
D.29 Builtin Date_to_Month .230
D.30 Builtin Date_to_Year.231
D.31 Builtin DELAY .231
D.32 Builtin delay .231
D.33 Builtin DELAY_TIME.232

61804-2 © IEC:2004(E) – 7 –
D.34 Builtin delayfor .232

D.35 Builtin DICT_ID .233

D.36 Builtin discard_on_exit.233

D.37 Builtin display.234

D.38 Builtin display_builtin_error.234

D.39 Builtin display_comm_error.234

D.40 Builtin display_comm_status.235

D.41 Builtin display_device_status .235

D.42 Builtin display_dynamics.236
D.43 Builtin display_message .236
D.44 Builtin display_response_code.237
D.45 Builtin display_response_status .238
D.46 Builtin display_xmtr_status .238
D.47 Builtin edit_device_value .238
D.48 Builtin edit_local_value .239
D.49 Builtin ext_send_command .240
D.50 Builtin ext_send_command_trans.240
D.51 Builtin fail_on_all_comm_errors .241
D.52 Builtin fail_on_all_response_codes .242
D.53 Builtin fail_on_comm_error .242
D.54 Builtin fail_on_response_code .243
D.55 Builtin fassign.243
D.56 Builtin fgetval .244
D.57 Builtin float_value.244
D.58 Builtin fsetval .244
D.59 Builtin ftoa.245
D.60 Builtin fvar_value.245
D.61 Builtin get_acknowledgement.245
D.62 Builtin get_comm_error.246
D.63 Builtin get_comm_error_string .247
D.64 Builtin get_date .247

D.65 Builtin get_date_value .247
D.66 Builtin get_dds_error .248
D.67 Builtin GET_DEV_VAR_VALUE .249
D.68 Builtin get_dev_var_value.249
D.69 Builtin get_dictionary_string.250
D.70 Builtin get_double.250
D.71 Builtin get_double_value.251
D.72 Builtin get_float .251
D.73 Builtin get_float_value .252
D.74 Builtin GET_LOCAL_VAR_VALUE .252
D.75 Builtin get_local_var_value .253
D.76 Builtin get_more_status .253

– 8 – 61804-2 © IEC:2004(E)
D.77 Builtin get_resolve_status.254

D.78 Builtin get_response_code.254

D.79 Builtin get_response_code_string .255

D.80 Builtin get_signed.255

D.81 Builtin get_signed_value.256

D.82 Builtin get_status_code_string .256

D.83 Builtin get_status_string .257

D.84 Builtin get_stddict_string.257

D.85 Builtin get_string .258
D.86 Builtin get_string_value .259
D.87 Builtin GET_TICK_COUNT .259
D.88 Builtin get_unsigned .259
D.89 Builtin get_unsigned_value .260
D.90 Builtin iassign.260
D.91 Builtin igetval .261
D.92 Builtin IGNORE_ALL_COMM_STATUS .261
D.93 Builtin IGNORE_ALL_DEVICE_STATUS .262
D.94 Builtin IGNORE_ALL_RESPONSE_CODES .262
D.95 Builtin IGNORE_COMM_ERROR .263
D.96 Builtin IGNORE_COMM_STATUS .263
D.97 Builtin IGNORE_DEVICE_STATUS .264
D.98 Builtin IGNORE_NO_DEVICE .264
D.99 Builtin IGNORE_RESPONSE_CODE .265
D.100 Builtin int_value.265
D.101 Builtin is_NaN .266
D.102 Builtin isetval.266
D.103 Builtin ITEM_ID .266
D.104 Builtin itoa.267
D.105 Builtin ivar_value.267
D.106 Builtin lassign.267
D.107 Builtin lgetval .268

D.108 Builtin LOG_MESSAGE .268
D.109 Builtin long_value .268
D.110 Builtin lsetval.269
D.111 Builtin lvar_value.269
D.112 Builtin MEMBER_ID.269
D.113 Builtin method_abort.270
D.114 Builtin ObjectReference .270
D.115 Builtin process_abort.270
D.116 Builtin put_date .271
D.117 Builtin put_date_value .271
D.118 Builtin put_double.272
D.119 Builtin put_double_value.272

61804-2 © IEC:2004(E) – 9 –
D.120 Builtin put_float .273

D.121 Builtin put_float_value .273

D.122 Builtin PUT_MESSAGE .274

D.123 Builtin put_message .274

D.124 Builtin put_signed.275

D.125 Builtin put_signed_value.275

D.126 Builtin put_string .276

D.127 Builtin put_string_value .276

D.128 Builtin put_unsigned .277
D.129 Builtin put_unsigned_value .278
D.130 Builtin READ_COMMAND.278
D.131 Builtin read_value.279
D.132 Builtin remove_abort_method (version A).279
D.133 Builtin remove_abort_method (version B).280
D.134 Builtin remove_all_abort_methods .280
D.135 Builtin resolve_array_ref.280
D.136 Builtin resolve_block_ref.281
D.137 Builtin resolve_param_list_ref.281
D.138 Builtin resolve_param_ref .282
D.139 Builtin resolve_record_ref .282
D.140 Builtin retry_on_all_comm_errors.283
D.141 Builtin RETRY_ON_ALL_COMM_STATUS .283
D.142 Builtin RETRY_ON_ALL_DEVICE_STATUS .284
D.143 Builtin RETRY_ON_ALL_RESPONSE_CODES .284
D.144 Builtin retry_on_all_response_codes.285
D.145 Builtin RETRY_ON_COMM_ERROR .285
D.146 Builtin retry_on_comm_error.286
D.147 Builtin RETRY_ON_COMM_STATUS .286
D.148 Builtin RETRY_ON_DEVICE_STATUS .287
D.149 Builtin RETRY
...