f16bmathis
Member
MicroLogix 1100, sending a MSG to another PLC. How would I stop it from constantly sending the MSG?
Thanks!
Thanks!
Msg sends data constantly
- Thread starter f16bmathis
- Start date
bernie_carlton
Lifetime Supporting Member + Moderator
Please post the program or at least a CLEAR screen shot of the relevant portion of the program.
James Mcquade
Member
this is from memory.
you must set up a heartbeat signal.
send a message to the plc a.
in that packet, set a bit.
when plc a gets the message, reset that bit.
when the ml1400 sees that the bit is clear, start a timer of x seconds.
send next message.
if plca does not get message, the ml1400 can set a fault bit.
the same logic is true for plca.
there is more to it than this, but its close.
hope this helps,
james
you must set up a heartbeat signal.
send a message to the plc a.
in that packet, set a bit.
when plc a gets the message, reset that bit.
when the ml1400 sees that the bit is clear, start a timer of x seconds.
send next message.
if plca does not get message, the ml1400 can set a fault bit.
the same logic is true for plca.
there is more to it than this, but its close.
hope this helps,
james
f16bmathis
Member
OP
I don't have a url I can post the picture at, so how about this?
-----II--------MSG
That's it so far! The first contact is an examine if open, MSG10
N, though I know it's not going to work with only this logic. The second is the MSG box that is set to send F8:0 to another PLCs F8:5.I'm looking at heartbeat logic and timer, but then would I need a MSG from the second PLC back to the first to enable the MSG received bit?
f16bmathis
Member
OP
The MSG box has an area for a bit for message done, message transmitting and message enabled, though I can only change Message enabled to a "1"
Ken Roach
Lifetime Supporting Member + Moderator
You can make picture files (BMP, JPG, PNG, etc) show up by simply attaching them to a post. They'll just show up underneath your text, without needing an external host for a URL link like the Insert Image function in the toolbar does.
A simple way to repeat a MSG instruction after a delay is to use a timer that starts when the /DN or the /ER bit turns on. When the timer is complete, an OTU (output Unlatch) is used to toggle off the /EN bit of the message which is otherwise constantly enabled.
A simple way to repeat a MSG instruction after a delay is to use a timer that starts when the /DN or the /ER bit turns on. When the timer is complete, an OTU (output Unlatch) is used to toggle off the /EN bit of the message which is otherwise constantly enabled.
f16bmathis
Member
OP
That looks great! I'll use it, looks so simple too. Thanks!
f16bmathis
Member
OP
I have this installed, but I constantly get an ERR. Target node cannot respond because of incorrect command parameters or unsupported command.
I have the size in elements set at 40, cause I don't know any better! Communication command is set to 500CPU read, cause I want it to read my location F8:0, it's data at F8:0 in a ML 1100, going to a 5/05 at F8:5.
Anything else? Thanks again!
Ken Roach
Lifetime Supporting Member + Moderator
A "500CPU Read" requests data from the Target Device and places it into the Data Table Address in "This Controller".
A "500CPU Write" takes data from the Data Table Address in "This Controller" and writes it into the Data Table Address in the "Target Device".
According to what you've written in this thread, you want the value in F8:0 in your MicroLogix 1100 to be written into the data table address F8:5 in an SLC-5/05 controller.
The MicroLogix 1100 is where the MSG instruction is created and executed by your program. It is the "This Controller" in the MSG configuration dialog.
You want a 500CPU Write, and you want the Size in Elements to be 1.
A "500CPU Write" takes data from the Data Table Address in "This Controller" and writes it into the Data Table Address in the "Target Device".
According to what you've written in this thread, you want the value in F8:0 in your MicroLogix 1100 to be written into the data table address F8:5 in an SLC-5/05 controller.
The MicroLogix 1100 is where the MSG instruction is created and executed by your program. It is the "This Controller" in the MSG configuration dialog.
You want a 500CPU Write, and you want the Size in Elements to be 1.
f16bmathis
Member
OP
Ken, Thanks, Just came back to say I changed the element size to 1 and it seems to be working. Also had earlier changed it from read to write.
It is working, I can see the value on F8:5 on the 5/05!
Thanks again!
Similar Topics
I'm using a SLC typed write from the ControlLogix5572 to the MicroLogix 1400, with path: 2, (MicroLogix IP). The ControlLogix equipment has a...
I have an 1769-L16ER that I use to test code and I just found that I can't create MSG tags at the local program scope - they have to be done at...
I have a client who periodically experiences network communication issues. Sometimes when I VPN into the site, their SCADA systems will flash comm...
I'm trying to read/write to an SLC5 with a ControlLogix L71 V35 plc that fails.
The exact same code works on an L82S with V32.
Is there a known...
Hello all,
I am currently trying to establish a message instruction to pass data from a 1756-L73 to a 1756-L71. My communication path from the...