1747 dtam

I have a 5/04 SLC hooked up to a 1747 DTAM. Using a link coupler, which from what I gather is DH485. I have some msg instructions in the program that tell if their are various faults. When I toggle one of the bits to trigger the msg instruction I get a timeout error 37 on the msg instruction on the program. The instruction is configured for channel 1, which is 57.6 K so I don't know if this could cause some issues or not. Wondering what channel I should be using. Also, currently their is communication between the DTAM and PLC cause you can access the timers, counter, etc. The only thing not working is the ASCII letter display from the PLC to the DTAM.

tietsortr said:

I have a 5/04 SLC hooked up to a 1747 DTAM. Using a link coupler, which from what I gather is DH485. I have some msg instructions in the program that tell if their are various faults. When I toggle one of the bits to trigger the msg instruction I get a timeout error 37 on the msg instruction on the program. The instruction is configured for channel 1, which is 57.6 K so I don't know if this could cause some issues or not. Wondering what channel I should be using. Also, currently their is communication between the DTAM and PLC cause you can access the timers, counter, etc. The only thing not working is the ASCII letter display from the PLC to the DTAM.

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From the User Manual (Publication 1747-6.1) Overview Chapter:

Important: The DTAM module does not support the floating point,
string, and ASCII data values that can be used with
SLC 5/03 ™ OS301 and later processors.

Something is missing.

Channel 1 on a SLC5/04 is a DH+ port, that will not connect to your 1747-DTAM.

So how is the DTAM connected to the processor? You mentioned a link coupler, what is it connected to?

http://literature.rockwellautomation.com/idc/groups/literature/documents/rn/1747-rn008_-en-p.pdf

The DTAM user manual shows a good diagram of what the communication connection is. Under chapter 2 the connection to DH485 network using link couplers. Its the last diagram in chapter 2.

http://www.magnetomechanical.com/resources/PDF_Manuals/DTAM-1747.PDF

As far as the DTAM supporting the msg instruction for a 5/04 I don't really see in chapter 8 under messaging instructions where it willn't support it. I do see where you sited that under chapter 1. So does this mean that you cant use the msg instruction with the 5/04.

On the msg instruction in rslogix 500 the setup screen under this controller shows they are using channel 1. When I go to to the channel configuration it shows channel one as DH+ at 57.6 K baud rate. I found in the user manual that the DTAM is 19.2 baud and the two have to be the same. The only confusing thing is that I can go to the DTAM and manually type in the starting word for the msg instruction and it will display the decimal value of that word. Could this be because the msg instruction specifically asks for what channel to write over, which is causing a baud rate conflict. Would this mean I would have to change the channel under the setup screen for the msg instruction from 1 to 0. If this is the case would I also have to change the status bit S:33/5 or S:33/6. Cause right now with channel 1 the status bit S:2/15 is a one. I have found other posts that talk about changing the status bits as well. Not 100% on their function.

You cannot use the DH+ port for your DTAM.

The last diagram is using the serial port on your SLC5/04, that would be channel 0.

Channel 0 should be configured for DH485 protocol. Make sure the baud rate is the same as the DTAM.

Is there anything connected to the DH+ port? There could be other devices connected to the DH+ network that are using message instruction(s) to pass info.

Yea. The cable coming from the processor to the link coupler is RS232. Theirs nothing plugged into any of the other ports on the 5/04. Theirs a DH+ pin connector and what looks like a scanport. The only one in use is the RS232. The DTAM LED is flashing green and communicating over RSlinx. I can see the device when I go online. The only problem is that when the msg instruction is true it doesn't display on the DTAM screen. If the msg instruction is set to channel 1 will it still be able to communicate through the RS232 port and down through the link coupler. Not sure which channel to use with this instruction.

As I said it the other post channel 1 is the DH+ port.

You need the message instruction(s) to use channel 0. (the serial port ), it should be configured for DH485. You can check this by looking at the channel configuration in RSLogix.


FYI, the round port ( you called a scanport) is a DH+ port electrically in parallel with the 3 pin DH+ port on your SLC5/04.

Thanks for the help. I changed the channel on the msg instruction from 1 to 0 tested the instruction and the DTAM showed the message.

tietsortr said:

Thanks for the help. I changed the channel on the msg instruction from 1 to 0 tested the instruction and the DTAM showed the message.

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You're welcome