X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=decoders%2Fmodbus%2Fpd.py;h=1d012e4560170aa05b3cebfc47defa2f3a9d3b8f;hb=7714a23058fcf1fbffa1208fb02f854947f0617f;hp=2404312ba8e760a1093aa618fa76553178150ca6;hpb=b197383cfb39b39ff04644855eef57f5d3c18bc1;p=libsigrokdecode.git diff --git a/decoders/modbus/pd.py b/decoders/modbus/pd.py index 2404312..1d012e4 100644 --- a/decoders/modbus/pd.py +++ b/decoders/modbus/pd.py @@ -22,6 +22,7 @@ from math import ceil RX = 0 TX = 1 +rxtx_channels = ('RX', 'TX') class No_more_data(Exception): '''This exception is a signal that we should stop parsing an ADU as there @@ -124,18 +125,18 @@ class Modbus_ADU: self.annotation_prefix + 'error', 'Message too short or not finished') self.hasError = True - if self.hasError and self.parent.options['channel'] == 'RX': - # If we are on RX mode (so client->server and server->client - # messages can be seperated) we like to mark blocks containing - # errors. We don't do this in TX mode, because then we interpret - # each frame as both a client->server and server->client frame, and + if self.hasError and self.parent.options['scchannel'] != self.parent.options['cschannel']: + # If we are decoding different channels (so client->server and + # server->client messages can be separated) we like to mark blocks + # containing errors. We don't do this when decoding the same + # channel as both a client->server and server->client frame, and # one of those is bound to contain an error, making highlighting # frames useless. self.parent.puta(data[0].start, data[-1].end, 'error-indication', 'Frame contains error') if len(data) > 256: try: - self.puti(len(data) - 1, self.annotation_prefix + 'error', + self.puti(len(data) - 1, 'error', 'Modbus data frames are limited to 256 bytes') except No_more_data: pass @@ -819,6 +820,7 @@ class Decoder(srd.Decoder): license = 'gplv3+' inputs = ['uart'] outputs = ['modbus'] + tags = ['Embedded/industrial'] annotations = ( ('sc-server-id', ''), ('sc-function', ''), @@ -842,11 +844,17 @@ class Decoder(srd.Decoder): ('error-indicator', 'Errors in frame', (14,)), ) options = ( - {'id': 'channel', 'desc': 'Server -> client channel', 'default': 'RX', - 'values': ('RX', 'TX')}, + {'id': 'scchannel', 'desc': 'Server -> client channel', + 'default': rxtx_channels[0], 'values': rxtx_channels}, + {'id': 'cschannel', 'desc': 'Client -> server channel', + 'default': rxtx_channels[1], 'values': rxtx_channels}, + {'id': 'framegap', 'desc': 'Inter-frame bit gap', 'default': 28}, ) def __init__(self): + self.reset() + + def reset(self): self.ADUSc = None # Start off with empty slave -> client ADU. self.ADUCs = None # Start off with empty client -> slave ADU. @@ -904,7 +912,7 @@ class Decoder(srd.Decoder): # somewhere between seems fine. # A character is 11 bits long, so (3.5 + 1.5)/2 * 11 ~= 28 # TODO: Display error for too short or too long. - if (ss - ADU.last_read) <= self.bitlength * 28: + if (ss - ADU.last_read) <= self.bitlength * self.options['framegap']: ADU.add_data(ss, es, data) else: # It's been too long since the last part of the ADU! @@ -921,11 +929,13 @@ class Decoder(srd.Decoder): def decode(self, ss, es, data): ptype, rxtx, pdata = data + # Ignore unknown/unsupported ptypes. + if ptype not in ('STARTBIT', 'DATA', 'STOPBIT'): + return + # Decide what ADU(s) we need this packet to go to. # Note that it's possible to go to both ADUs. - if rxtx == TX: - self.decode_adu(ss, es, data, 'Cs') - if rxtx == TX and self.options['channel'] == 'TX': - self.decode_adu(ss, es, data, 'Sc') - if rxtx == RX and self.options['channel'] == 'RX': + if rxtx_channels[rxtx] == self.options['scchannel']: self.decode_adu(ss, es, data, 'Sc') + if rxtx_channels[rxtx] == self.options['cschannel']: + self.decode_adu(ss, es, data, 'Cs')