Next Advance SP570-M - Manual (Page 28)

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SP500 series OEM Programmable Syringe Pump
NE500 series manual 23 Revision 101101
Communications to and from the pump use the following data frame:
Supported RS-232 Data Frames
Baud rate:
19200
Frame: 10 bit data frame (8N1):
Start bit:
1
Data bits: 8
Stop bits: 1
Parity:None
Every command received by a pump in the network is acknowledged by the pump with a response packet
that includes a status character indicating the current operational state of the pump.
Two packet protocols are supported, Basic and Safe. The enabled communications protocol is stored in
non-volatile memory, and therefore will be in affect at power up. Safe Mode provides a safer
communications protocol than Basic Mode. Safe Mode detects corrupted data and loss of communication,
as well as automatically transmitting status packets when an alarm occurs.
Considering that the 19200 baud rate communicates at 52 s per bit, a small glitch on the RS-232 cable,
flipping a single bit, can convert a transmitted infusion rate of 100 ml/hr into 900 ml/hr, the need for the
Safe Mode in a production environment is evident. However, Basic Mode is excellent for simplifying
early development of a control program.
While in the Basic Mode, the pump will accept either communications protocol, Basic or Safe. Though
the response packet will be in the current communications mode. This allows a computer’s
communication’s driver to be designed with just one mode. A Safe Mode communications driver can send
a ‘SAF’ command to the pump in the Safe Mode protocol while the pump is in Basic Mode. The response
to the ‘SAF’ command, enabling Safe Mode, will then be in the Safe Mode protocol.
8.3.1 RS-232 General Syntax Legend
The following syntax expansion legend is common to all syntax expansions:
Except where indicated, all command and response characters are ASCII data.
<float> => <f> [ <float> ] Floating point number. Maximum of 4 digits plus 1
decimal point. Maximum of 3 digits to the right of
the decimal point.
<volume units> => UL l (microliters)
ML ml (milliliters)
<TTL level> => 1 TTL high level
0 TTL low level
<on-off> => 1 On, enabled
0 Off, disabled
<phase data> => <n> [<n>] Program Phase number. Valid values: 1 to 41
<count data> => <n> [<n>] Valid values: 1 to 99
<number data> => <n> [<n>] Valid values: 0 to 99
<text> => "any printable character" [<text>]
<f> => { <n> | . } Floating point digits
<n> => { 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 } Digits
<byte> => “one byte of any data”
( ) One byte of data expressed as (0xhh), where ‘hh’ is
the data in hexadecimal.
=> Is defined by. Syntax expands to next level of
expansion.