Let’s talk for a moment about how the pumps are connected. An understanding of this will help you diagnose communications problems with your pumps.
The pumps are connected in a daisy chain to form a network. Each pump listens to all of the commands sent down the wire. All pumps see all the commands at the same time.
Pump network diagram
The pumps only obey commands after they have ‘heard’ their address number come down the line. There is a special address ‘*’ which all pumps obey.
This means that all pumps on a network MUST :
- Be set to the same communications parameters in order for the commands to travel down the network and be understood by all the pumps.
- Be connected into the daisy chain correctly and securely to participate in the network.
- Be set to a unique address. Two pumps set to the same address will answer commands at the same time and cause communications to become garbled for all pumps on the network.
To Computer socket on the rear of a pump
|Location of RS232 connectors on pump rear – NOT the db9 connector
||NE-500 OEM style pump with a serial cable in the db9 connector (lower connector). Dont do it!
Communications Check List
Here are the things that you need to do in order to have a pump communicate.
- Configure SyringePumpPro with the correct communications port, See Determining the Com Port
- Configure SyringePumpPro to communicate at the correct baud rate
- Pump needs to be connected with the correct cable, to the correct port on your computer,
- Pump needs to be turned on.
- Each pump in the network needs to be set at a unique pump address (if it is connected with other pumps). All pumps are shipped from the factory set to address 0.
- Pump and SyringePumpPro need to be talking in the same mode – use Basic
- There must be a pump configured with the address 0.
- All pumps on a network/port MUST be set to the same baud in order to work correctly.
- Pumps will be discovered in numerical order of their configured network address.
- Pumps configured with an identical address to another pump on the network will not be detected and will lead to communication problems with all pumps on the network.