Is there any way to control the start and stop of a pump located 2 kilometers away from the control room?

Sure. The control room can use a Tengkong PLC such as the T920, while remote operation can be achieved using the T902 remote module or another PLC like the T920

It depends on how many devices need to be controlled; if the number is small, a PLC is sufficient. Fiber optic communication is preferable, as GPRS is affected by service providers, and wireless connections may suffer from interference.

It is not recommended to use GPRS, as the signal quality is not very good due to the influence of service providers. Fiber optic transmission is an option, but multi-mode fiber cannot be used over long distances; you could consider single-mode fiber, although its cost is relatively high. I suggest using radio transmission, as it only costs a few hundred dollars per year, and the signal quality is good

1. Optical fibers offer the highest reliability, but an RTU and corresponding communication equipment must be installed on-site; this is how many automatic valve rooms in long-distance pipelines are operated today. 2. Using GPRS requires renting communication links from companies such as Mobile or Telecom, and performance may be affected by factors like signal coverage, resulting in lower reliability. It can be used if necessary, but a small interlock system should definitely be installed on-site to enhance security (for example, a system that triggers actions when the pressure at the pump outlet is too high or the pressure at the pump inlet is too low; systems with low power requirements can be powered by solar batteries). The on-site system should have an SOE function, allowing it to communicate with the central system once the communication link is restored

A communication distance of 5 kilometers can be achieved using CAN-485G remote drivers: By installing CAN-485G remote drivers at the communication ports of each PLC, as shown in the figure below, a maximum communication distance of 5 kilometers can be attained at a baud rate of 9600bps, while 3 kilometers can be achieved at 19200bps. This is likely the maximum distance that can be achieved via copper wiring without repeaters. CAN-485G is an isolated, transparent transmission driver; it does not use the CAN protocol but rather employs a transparent transmission method, so no modifications to the existing software are required when using CAN-485G! CAN signals have many advantages over RS485 signals; readers can refer to relevant articles on the website. Note: The cross-sectional area of the communication cable is larger than that of an RS485 cable; therefore, a 1mm2 twisted pair cable should be used. Since CAN-485G and CAN-232G (which connect to the RS232 port of a computer) are equipped with two pairs of bus terminals, wiring according to the diagram eliminates the need for any branch cables. 　　CAN-485G and CAN-232G are equipped with terminal resistors internally; the switch K for setting the terminal resistors at the beginning and end of the bus should be set to “R” (to connect 120-ohm terminal resistors), while it should be set to “OFF” for other stations (no terminal resistors to be connected).

You can refer to the following website: http://blog.cechina.cn/genghis/220879/message.aspx

Optical cable + optoelectronic conversion + PLC is one solution, but the cost of optical cables is much higher than that of ordinary shielded twisted pair cables. Therefore, it is recommended to adopt a solution using twisted pair + CAN-485G interface + PLC. Small PLCs are very cheap these days; depending on your situation, buying a small PLC from Siemens or Omron will solve the problem. Cable + PLC + CAN interface – it costs around 45,000 to 55,000 RMB. The price of the cable is around 15 to 20 yuan per meter. A small PLC with a CAN interface costs around 10,000 yuan.

Try to solve it with a mobile phone; using fiber optic cables for one pump is too troublesome