Teledyne D series Installation And Operation Manual page 168

D Series Syringe Pumps
Section 8 Serial Interface
Table 8-5 Example of a Visual C++ program to demonstrate conversion
of pump commands to DASNET frames (Continued)
char buf[2];
buf[0]=0;
/* get char if there
if(!ReadFile(hCom, buf, 1, &dwBytesRead, NULL))
{
//error occurred. Report to user.
}
return buf[0];
}
void comm_putc(char outchar)
{
DWORD dwBytesRead = 0;
char out[2];
out[0]=outchar;
if(!WriteFile(hCom, out, 1, &dwBytesRead, NULL))
{
//error occurred. Report to user.
}
}
8-14
*/
There are three types of operation within the network: network
controller, master, and slave. A computer typically serves as the
network controller. It supervises all data flow on the network. It
also polls each unit which initiates data transfer and commands.
Note
The network controller (typically a PC) should not be confused
with the pump controller. The network controller is used in
addition to the pump controller.
The slave unit simply responds to commands accordingly. The D
Series pump functions as a slave unit. These functions may be
combined in one unit; i.e., a computer can function as both a
network controller and a master.
All data transfers are in a frame format. When the network con-
troller polls an instrument, it will start to respond within 200 ms.
If it does not reply, it will be polled again. If after three attempts
at polling it does not reply, it will be dropped from the polling
rotation. When the instrument does respond, the polling rotation
does not advance until an error-free transfer has occurred.
The frame format for data transfers from the network controller
is as follows:
destination\acknowledgement\message source
\length\message\checksum\[CR]
• The destination is the 1-digit unit identification
number of the instrument to receive the message.