understanding checksum of ascii string

Question

I am reading a manual on sending commands via serial to a device as shown:

Assume that my equipment address is 000. I would send a command like: ">000P**cr".

what would **, my checksum be? According to the manual, I need the last two digits of the total char code of "000P".

Isn't that just the hex value of "P"? I can't seem to understand this.

Answer 1

Yes it's a bit confused, but my guess would be:

total = ascii('0') + ascii('0') + ascii('0') + ascii('P')
total = 48 + 48 + 48 + 80
total = 224

cksum = last2digits(total) = 24

If it does not work as is, maybe try in hexadecimal notation:

hex(total) = E0
hex_cksum  = last2digits(hex(total)) = E0