RS232 dual connection, does it exist?

[LowRange]

I'd like to connect my laptop AND proface HMI to an SLC 5/04 1747 L541 so I can look at the bit address of some of the HMI buttons. I don't have access to whatever software is used with Proface HMI to look at the button addressing so I'd like to connect to the controller, smack a button and see which instruction, on what ladder in which rung, goes true. The purpose here is to create a Factorytalk View ME application and get rid of the Proface HMI and replace it with a PVP+ 1000 using the existing RSlogix 500 project.

The problem: I've got only the one rs232 serial port and two things can't be trying to talk through it at the controller at the same time. What's the workaround you guys typically use to deal with this? Is there some way to track whether an instruction has been toggled (by HMI) from a true to false state? I dunno maybe, upload a copy of the project, save it, connect to the HMI, push a button and then upload another copy of the project and use the compare tool to compare the two copies of the project?

I'd like to push a button on the HMI, disconnect the HMI from controller, connect the laptop to the controller and see what the HMI button has changed in the Rslogix 500 project.

 

[cjd1965]

buy a usb to rs232 adapter...keyspan is popular

 

[LowRange]

buy a usb to rs232 adapter...keyspan is popular

I have one. It is how I connect the laptop to rs232 serial. I want to have both the laptop and HMI talking to the controller at the same time but the controller only has one rs232 serial port and that serial port is its only means of communication.

 

[JordanCClark]

You may be able to find a used 1770-KF2 on E-Bay as an stop-gap solution. You can then set your PC on the DH+ side.

Don't know if I'd use it in an always-on activity, as it would be used, but this may give you other options.

 

[ASF]

Your other option - which will be more painful, but free - is some diagnostic code in the PLC. For each bit in the PLC that you know is attached to a button, write some code like this...

|  Button_1      Button_1_Pressed
|----| |---------------( L )--|
|
|  Button_2      Button_2_Pressed
|----| |---------------( L )--|
|
|  Button_3      Button_3_Pressed
|----| |---------------( L )--|
|
|  Button_4      Button_4_Pressed
|----| |---------------( L )--|
|

Then connect your HMI to the PLC, press a button, connect your laptop back in, and see which latch has been set.

Painful, because you have to do it one at a time, and go online/offline between each test. But it doesn't require any extra hardware.

Just remember to toggle the latched bits back off before you run the next test, to avoid confusing yourself

 

[Firejo]

If the driver running in the SLC5/04 is a DF1 half duplex master than you could use an RS232 splitter and create a DF1 half duplex slave driver in RSLinx (then use RSLogix 500) but the driver in the SLC would need to be configured to talk to the node number in the HMI and the node number you would set up in RSLinx. However, it’s very unlikely that the driver in the SLC is a DF1 half duplex master. It’s probably a DF1 full duplex driver in which case it will only talk to one other DF1 full duplex device (the HMI). What you need is a USB to DH+ adaptor (1784-U2DHP) so that you can run DH+ in RSLinx and use that to get into the SLC. That being said, it would be cheaper to replace the SLC5/04 with an SLC5/05 which would give you an Ethernet connection to the processor. That would also give you the option of connecting the PV+ to the SLC via Ethernet. The 1784-U2DHP sells for around $1500.00 to $1700.00 which is a… well I’ll let you decide what to call that.

 

[LowRange]

Your other option - which will be more painful, but free - is some diagnostic code in the PLC. For each bit in the PLC that you know is attached to a button, write some code like this...

|  Button_1      Button_1_Pressed
|----| |---------------( L )--|
|
|  Button_2      Button_2_Pressed
|----| |---------------( L )--|
|
|  Button_3      Button_3_Pressed
|----| |---------------( L )--|
|
|  Button_4      Button_4_Pressed
|----| |---------------( L )--|
|

Then connect your HMI to the PLC, press a button, connect your laptop back in, and see which latch has been set.

Painful, because you have to do it one at a time, and go online/offline between each test. But it doesn't require any extra hardware.

Just remember to toggle the latched bits back off before you run the next test, to avoid confusing yourself

Very clever. This is exactly why PLCs.net is my go to PLC and MHI resource. I have few N7 address that are suspect and throwing in a latch instruction would allow me to sort out which one correlates with each button. Thank you.

 

[ASF]

Glad I could help! Have fun

 

[GaryS]

I think what you want is a data tap
http://www.bb-elec.com/Products/Serial-Connectivity/Serial-Data-Tools-Adapters/Data-Taps.aspx
check this link

 

[Mickey]

A port splitter may work..

http://literature.rockwellautomation.com/idc/groups/literature/documents/in/1747-in516_-en-p.pdf

 

[Gil47]

Is your SLC 5/04 currently connected to a DH+ network.

or

Do you have a Laptop that can access DH+

 

[CRMCC]

if you also added a timer after each latch then you could press each button then wait a second or two then press the next button, do this for all buttons before disconnecting the HMI.

Code:
| Button_1 Button_1_Pressed
|----| |---------------( L )--|
|
| Button_2 Button_2_Pressed
|----| |---------------( L )--|
|
| Button_3 Button_3_Pressed
|----| |---------------( L )--|
|
| Button_4 Button_4_Pressed
|----| |---------------( L )--|
|

 

[ASF]

What

If you're going to resurrect a 6-month old thread, I would hope you'd have a slightly more detailed question to ask...

 

[JaxGTO]

I would call your AB distributor and see if you can borrow a Logix rack Ethernet card and a DHRIO card. Most of the PLC experts keep them on hand. Then just use that as a gateway to get to the PLC over Ethernet to DH+.

 

[GaryS]

the big problem is that in RS232 every port reads everything all the time. but here are some times ways to control the write to a port.
as port switch may do what you need
check this out.
http://www.bb-elec.com/Products/Ser...Data-Tools-Adapters/Serial-Data-Switches.aspx