https://ni.lithium.com/t5/Lookout/Read-Write-a-bit-in-a-Modbus-Address/m-p/37814#M702 Greetings,<BR />I'm working on a project for a customer of mine. I'm working off of his I/O mapping list. We are using MODBUS to communicate to a Motorola MOSCAD FIU. According to the I/O Map, I need to read a bit from address 307682:01 which normal I would translate into 307682.1 but Lookout is not excepting this address as a valid Data Member. So I did some troubleshooting of my own and found that Modbus Data member (307682) is only used as "a 6-digit addresses of 16 bit input registers encoded as unsigned binary integers ranging from 0 - 65535." I guess an analog value.<BR /><BR />Is my thought process correct on this? Does my customer need to change his I/O mapping. Am I overlooking something?<BR /><BR />Attached is a copy of the I/<BR />O map. <BR />Oliver Scheurer<BR />Aegis Solutions, Inc.<BR />2660-T Yonkers Road<BR />Raleigh, NC 27604<BR />Phone: (919) 861-0103 Ext. 231<BR />Fax: (919) 861-0104<BR />www.aegis-solutions.com <BR /> Fri, 15 Mar 2002 16:02:40 GMT Ollie 2002-03-15T16:02:40Z https://ni.lithium.com/t5/Lookout/Read-Write-a-bit-in-a-Modbus-Address/m-p/37814#M702 Greetings,<BR />I'm working on a project for a customer of mine. I'm working off of his I/O mapping list. We are using MODBUS to communicate to a Motorola MOSCAD FIU. According to the I/O Map, I need to read a bit from address 307682:01 which normal I would translate into 307682.1 but Lookout is not excepting this address as a valid Data Member. So I did some troubleshooting of my own and found that Modbus Data member (307682) is only used as "a 6-digit addresses of 16 bit input registers encoded as unsigned binary integers ranging from 0 - 65535." I guess an analog value.<BR /><BR />Is my thought process correct on this? Does my customer need to change his I/O mapping. Am I overlooking something?<BR /><BR />Attached is a copy of the I/<BR />O map. <BR />Oliver Scheurer<BR />Aegis Solutions, Inc.<BR />2660-T Yonkers Road<BR />Raleigh, NC 27604<BR />Phone: (919) 861-0103 Ext. 231<BR />Fax: (919) 861-0104<BR />www.aegis-solutions.com <BR /> Fri, 15 Mar 2002 16:02:40 GMT https://ni.lithium.com/t5/Lookout/Read-Write-a-bit-in-a-Modbus-Address/m-p/37814#M702 Ollie 2002-03-15T16:02:40Z https://ni.lithium.com/t5/Lookout/Read-Write-a-bit-in-a-Modbus-Address/m-p/37815#M703 WOW!!.. I get to answer my own question. You all are slow... J/K...<BR /><BR />Anyway, the fine people at NI Tech Support Helped me out with this one. Seems that it is a problem related to Lookout and Modbus. After discussing this problem with a few engineers, I decided to call the customer and let him know of his mistake. Well, he proceeded to tell me that "Wonderware can do it with out a problem". So I called NI Support again, and they told me that further research showed that it is something that was not put into Lookout. The Support engineer started a "CARD?". But he also gave me a work around.<BR /><BR />1. create an expression<BR />2, enter getbit(3,1)<BR /><BR />This expression will return a ON status since the number 3 in binary is 1 1 and looking at the first bit is 1.<BR /><BR />So for my<BR /> application I would use<BR />getbit(modbus1.307682,1)<BR /><BR />I hope this makes sense.<BR /><BR />Oliver Scheurer<BR />Aegis Solutions, Inc.<BR />2660-T Yonkers Road<BR />Raleigh, NC 27604<BR />Phone: (919) 861-0103 Ext. 231<BR />Fax: (919) 861-0104<BR />www.aegis-solutions.com <BR /> Fri, 15 Mar 2002 21:37:42 GMT https://ni.lithium.com/t5/Lookout/Read-Write-a-bit-in-a-Modbus-Address/m-p/37815#M703 Ollie 2002-03-15T21:37:42Z