If the product is an AiRanger / SITRANS LU Version 5.23 or above, and P762 is used to turn on the Point Alarm and status bits, then the additional bits are defined: Applicaton Layer Words 21 to 30: Returned Values, MPA These words contain values requested by writing to words 1 to 4 of the Write Block. The type of data and format are specified with that request, and returned in Read words 31 to 34. Words 31 and 32; 33 and 34: Decimal Place, Format, Parameter Number and Sec- ondary Index, MPA These words contain the last values written to Write block words 1 and 4. These words indicate what information is contained in Read block words 21 to 30.
These words are provided since there can be a delay between writing a request via a Write, and the appearance of the requested values. Use these words as an indicator that the requested information is updated. Words 35 to 37 and 39 to 41: Parameter Number / Primary Index / Secondary Index and Decimal Place / Format / Read Write Flag, SPA These words contain the last values written to words 5 to 7 and 9 to 11 of the Write block. They confirm that the parameter value has been written. These words are not updated until the value has been successfully transferred and stored in the Siemens Milltronics SmartLinx instrument. See Write formats on page 28 for details. Word 38:
Returned Value, SPA This word contains the current value of the parameter identified by words 35 to 37 and 39 to 40, regardless of the value of word 11 (Write flag). If this value does not change when a new value is written to word 8 (Parameter Value) then check the following: 1. Words 5 to 7 and 9 to 10 of the Write block should match words 35 to 37 and 39 to 40 of the Read block: if not, then the instrument hasn’t responded yet. 2. If words 5 to 7 and 9 to 10 of the Write block do match words 35 to 37 and 39 to 40, of the Read block, then the parameter value has not been updated.
Check that the Siemens Milltronics SmartLinx instrument is in PROGRAM mode and that the program lock (P000) is not on, then try again. Page 32 SmartLinx DeviceNet – INSTRUCTION MANUAL 7ML19981BH02 Bit Description 04 Low-Low Alarn (1=ON) Low Alarm (1=ON) High Alarm (1=ON) High-High Alarm (1=ON) 05 06 07