RS-232 Programming Problem With SLC/500

[Mark Nash 0]

Hi I am trying to write some code to control an Agilent DACU from an SLC/500. I have the code to setup the DACU and read the results. The problem is with how it has to be done. The DACU could have up to 120 channels to get readings from. I can only do 5 channels at a time due to buffer length restraints. Here is how it should work Start Loop Set up channels 101-105 Read channels 101-105 Store readings Setup channels 106-110 Read channels 106-110 Store readings Setup channels 111-115 Read channels 111-115 Store readings .... End Loop The current issue seems to be that the code is starting on the second group of channels, before the 1st group is finished. This causes the DACU to stop working all together I have attached the RSS file in question from RSLogix 500. Any help would be greatly appreciated. I have been programming various systems for 20 years, but this is my first time with a PLC and it is kicking my ***. Thanks Mark THIS_ONE_WORKS_VERSION_4.zip

[b_carlton 61]

You are doing hardly any interlocking, verifying that the ASCII instruction is done before beginning the next one. The instructions are trying to execute on top of each other. Serial instructions take TIME (many program scans) to complete. The AWA has an EM bit in its control which should be true before attempting to start the next AWA.