Re: Modbus Master Speed
Posted: Thu Oct 05, 2023 1:51 am
Hi
My questions are probably not the correct.... as I am not as advanced as you are.
However... As I understood (please correct me).
After Master_Local (Rs485) collects some information from different Slaves and save it to digi_inputs 08,09,10,11, and to Analog inputs 14_0 and 14_1...(etc),
The Slave for HMI monitor sends over Rs232 information to HMI Master (Xpanel).
Question.
What is the reason to use the HMI Master COM2: RS-232C but not the COM1: RS-422/485 ?
I read somewhere:
RS232 requires a minimum of 3 conductors to connect the two devices. Rx, Tx and Ground.
Some devices implement hardware handshaking. This means that before they send a message some voltage must be applied to one of the other pins on the port. If hardware handshaking is active on the device, then you will never get a response until you bypass it or implement it. We recommend bypassing it because there are often differences in the ways that vendors implemented it.
My questions are probably not the correct.... as I am not as advanced as you are.
However... As I understood (please correct me).
After Master_Local (Rs485) collects some information from different Slaves and save it to digi_inputs 08,09,10,11, and to Analog inputs 14_0 and 14_1...(etc),
The Slave for HMI monitor sends over Rs232 information to HMI Master (Xpanel).
Question.
What is the reason to use the HMI Master COM2: RS-232C but not the COM1: RS-422/485 ?
I read somewhere:
RS232 requires a minimum of 3 conductors to connect the two devices. Rx, Tx and Ground.
Some devices implement hardware handshaking. This means that before they send a message some voltage must be applied to one of the other pins on the port. If hardware handshaking is active on the device, then you will never get a response until you bypass it or implement it. We recommend bypassing it because there are often differences in the ways that vendors implemented it.