So I worked through a problem I had in trying to understand how output devices were linked via DeviceNet to the SLC-500 PLC that controls them. The system is a pneumatic assembly line.
I discovered that inputs and outputs were joined to 1792D modules. I have established how to monitor the state of inputs that are joined to the Armor Block, and also how they are mapped to the 1747-SDN DeviceNet scanner in the system.
I also know how the outputs are mapped in the scanner, but I don't know how to determine which outputs are controlled by which bits in the Armor Blocks output byte.
The Armor Block in question is a 4I/4O type (1792D-4BVT4D).
According to the manual for the block, bits 0 through 3 in the "consumed" byte are used to switch the outputs, but I am unable to view these bits in the parameter list for the block. (The byte in qestion does not show up in the list).
With RSNetwox open and setup to show my network, I right click the node whose outputs I know I am forcing on from the SLC500 - I have verified the node number by monitoring the inputs for the Armor Block.
I select "Monitor" to cycle through the parameters in real-time, then toggle the output in question via my SLC500 program. I do leave enough time for the monitoring cycle to go through all parameters before proceeding.
My problem is that I see nothing else in the list changing state when the outputs are toggled - are the output bits (in a consumed byte) accessed in some other way?
Thanks,
Richard Byrne.
I discovered that inputs and outputs were joined to 1792D modules. I have established how to monitor the state of inputs that are joined to the Armor Block, and also how they are mapped to the 1747-SDN DeviceNet scanner in the system.
I also know how the outputs are mapped in the scanner, but I don't know how to determine which outputs are controlled by which bits in the Armor Blocks output byte.
The Armor Block in question is a 4I/4O type (1792D-4BVT4D).
According to the manual for the block, bits 0 through 3 in the "consumed" byte are used to switch the outputs, but I am unable to view these bits in the parameter list for the block. (The byte in qestion does not show up in the list).
With RSNetwox open and setup to show my network, I right click the node whose outputs I know I am forcing on from the SLC500 - I have verified the node number by monitoring the inputs for the Armor Block.
I select "Monitor" to cycle through the parameters in real-time, then toggle the output in question via my SLC500 program. I do leave enough time for the monitoring cycle to go through all parameters before proceeding.
My problem is that I see nothing else in the list changing state when the outputs are toggled - are the output bits (in a consumed byte) accessed in some other way?
Thanks,
Richard Byrne.
