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Created by: plsmocke at: 7/17/2014 8:48 PM (2 Replies)

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7/17/2014 8:48 PM	Rate (1)
plsmocke Posts: 3 Rating: (1)	Hello, I am new to STL and would like someone to explain to me what is going on. Basically I am "AND"ing an always on bit after either a NOT or a CLR instruction. After the NOT, the RLO is a 0, but after a CLR the RLO is a 1. I would think they both should be setting the RLO to 0 but this is not the case, as you can see in my screenshot. Thank you, Pat Attachment STL Weird Stuff.jpg (188 Downloads)
plsmocke Posts: 3 Rating: (1)
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7/17/2014 8:58 PM	Rate (1)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/24/2025 Posts: 15558 Rating: (2468)	plsmocke Hello, I am new to STL and would like someone to explain to me what is going on. Basically I am "AND"ing an always on bit after either a NOT or a CLR instruction. After the NOT, the RLO is a 0, but after a CLR the RLO is a 1. I would think they both should be setting the RLO to 0 but this is not the case, as you can see in my screenshot. Thank you, Pat Maybe this thread will help: /tf/WW/en/Posts/44426
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7/18/2014 9:22 PM	Rate (0)
plsmocke Posts: 3 Rating: (1)	Thank you, I got it figured out from ur links. Here is the code I ended up with, fyi: TAR1 #AR1_Backup //Make a backup of AR1 to not cause program error. OPN #DB_Number //Open the Data Block that will be read/written from the user. L #IO_Addr_Of_Drive // Load Drive Address from user SLD 3 // Make Pointer from this value L P#0.0 +D T #Pointer_To_Drive // Store in the Pointer_To_Drive L 0 // Load the Byte address of where to write to in DB SLD 3 //Make Pointer from this value L P#0.0 +D T #Pointer_To_Byte_In_DB// Store in the Pointer_To_Byte_In_DB //DRIVE TO PLC - LOOP TO COPY FROM PIW TO DB L 20 T #Word_Amount //Amount of Words to be Read L #Word_Amount //Word Amount has to be in ACC before the loop starts DRIVE_TO_PLC : T #Word_Amount // Store Word Amount LAR1 #Pointer_To_Drive // Load AR1 with pointer to Drive L PIW [ AR1 , P#0.0 ] // Load one WORD from PI Area T #Temp_Data // Transfer to temporary storage +AR1 P#2.0 // Update Pointer to Drive by 2 because we're copying 2 bytes TAR1 #Pointer_To_Drive // Store back in Pointer to Drive variable LAR1 #Pointer_To_Byte_In_DB//Load AR1 with the Pointer of the DBB Location L #Temp_Data //Load the temporary data to be transfered T DBW [ AR1 , P#0.0 ] // Transfer to Data Block +AR1 P#2.0 //Update Pointer to DB by 2 because we're copying 2 bytes TAR1 #Pointer_To_Byte_In_DB//Store back in Pointer to Db variable L #Word_Amount // Load Word amount into ACC to be decremented by LOOP command LOOP DRIVE_TO_PLC // Loop: ends when Word Amount is 0 //The bytes in the Status Word from the Drive are swapped, this takes care of that. L 0 // Load byte address SLD 3 //Make a pointer out of this address L P#0.0 +D T #Pointer_To_Byte_In_DB//Transfer to a pointer LAR1 #Pointer_To_Byte_In_DB// Load AR1 with the pointer L DBW [ AR1 , P#0.0 ] // Load one WORD from the pointer CAW //Byte swap ACCU1's low word T DBW [ AR1 , P#0.0 ] //Transfer back to the DB //PLC TO DRIVE - LOOP TO COPY FROM DB TO PIQ OPN #DB_Number //Open DB again L #IO_Addr_Of_Drive // Load Drive Address from user SLD 3 // Make Pointer from this value L P#0.0 +D T #Pointer_To_Drive // Store in pointer to drive L 40 // Load starting byte address in DB SLD 3 //Make a pointer from this L P#0.0 +D T #Pointer_To_Byte_In_DB//Store in pointer to DBB L 12 T #Word_Amount //Amount of words in the input area L #Word_Amount //Word Amount has to be in ACC before the loop starts PLC_TO_DRIVE : T #Word_Amount // Store word amount LAR1 #Pointer_To_Byte_In_DB// Load AR1 with the pointer to the DB L DBW [ AR1 , P#0.0 ] // Load one word from the pointer T #Temp_Data // Transfer to temporary storage +AR1 P#2.0 // Update Pointer to DB by 2 because we're copying 2 bytes TAR1 #Pointer_To_Byte_In_DB//Store back in Pointer to Db variable //The Control Word is sent out swapped, so check to see if the loop is in the first loop to swap them. L #Word_Amount //Checks to see if the loop is the first loop, means the first word L 12 <>I JC Not_First_Word //If the loop is not on the first word, then skip the byte swap L #Temp_Data //If the loop is on the first word, then do the byte swap CAW T #Temp_Data Not_First_Word : LAR1 #Pointer_To_Drive//Load AR1 with the pointer to the drive L #Temp_Data //Load the temporary data to be transfered T PQW [ AR1 , P#0.0 ] // Transfer to PQ Area +AR1 P#2.0 // Update Pointer to Drive by 2 because we're copying 2 bytes TAR1 #Pointer_To_Drive //Store back in Pointer to Drive variable L #Word_Amount // Load Word amount into ACC to be decremented by LOOP command LOOP PLC_TO_DRIVE // Loop: ends when Word Amount is 0 //Exit FC LAR1 #AR1_Backup //Restore Address Register 1 SET SAVE //Enable ENO BEU //Exit FC Unconditionally
plsmocke Posts: 3 Rating: (1)
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